I think people are mostly concerned with muslims, in effect, whether they're arab or not. Take the Netherlands for example, it features a guy called Wilders who frequently talks about Eurabia (instead of Europe) and calls the labour party (partij van de arbeid) the partij van de arabieren (arabs). When in reality, 90% of muslims in the Netherlands are Berbers and Turks, not arabs. There's an anti-arab sentiment because people are ignorant, but it really doesn't matter if you're arab or not. You can be berber, pakistani, turkish, persian or kurdish and you'll be seen as an arab, which is wrong, and a muslim, which is usually correct. So it probably doesn't make all that much sense to talk about arabs.
So Islam instead, in Sweden:
> Islam has, as of 2009, 106,327 officially registered adherents among citizens and residents of Sweden. Other sources set the figure at roughly 450,000 to 500,000, which accounts for around 5% of the total Swedish population, including people who would not really regard themselves as Muslims.[1]
Of course, the distribution is quite lopsided and very much geared towards the big cities. Further, immigrant families (at least those from lower socioeconomic status, e.g. usually not say Iranian immigrants) tend to have a higher birthrate. Further, at old age immigrants tend to move back to their home country, relative to wanting to work in Europe at a younger age. The combination of these three effects: concentration in cities, relatively high birthrate and relatively high incoming young migrants vs outgoing older migrants, makes for large young populations in the big cities. And young people themselves have certain characteristics compared to older age groups (across ethnicities): relatively higher propensity to be present on the street, rather than at home, relatively higher unemployment (i.e. again, overrepresented in the street, underrepresented in workplaces), relatively higher levels of crime etc.
Such that a population of just 5% can be 15-20% in certain cities, a population which is disproportionately confronted on the street in a criminal or unemployed fashion, compared to other age groups (and due to the demographic age characteristic of particular ethnicities, also compared to other ethnicities). This can skew the personal experience of citizens of these cities in a way that average statistics wouldn't explain.
Combine this with further concentrations, like within neighbourhoods, and you get groups of people who feel overwhelmed by the demographic changes. For example, say 5% are 'foreign' in a particular country, but they're 4x more likely to live in a large city, and have 2x as many kids than the national average. Well then you've got 40% of the kids who are foreign in that city. And in a particular neighbourhood in that city, perhaps these foreigners are 2x more likely to live, such that if you send your kid to school, perhaps say 75% of the kids don't look like your kid, nor do the parents look like you or speak your language, perhaps even half of the teachers don't look like you. And for these people, I get it. I get the fear. I'm not saying it's right, but that it's very understandable. Of course these numbers are just made up, but you get my point.
I'm from a muslim family myself and I get frustrated with all the racist bs, I mean it's overwhelming what I faced as a teenager looking to shape his identity. Every day there were articles about people like me in the newspapers, describing me or my peers or family as barbaric, as having 'genes geared towards crime', as being backwards, less intelligent etc etc. Don't get me wrong, I reject all of that. But I do appreciate that some of the native white population in Europe feels threatened, and that it's not just blatant xenophobia. Indeed there are pockets where they're no longer the majority, and where the momentum is becoming disproportionate, and that can be scary. And simply saying 'but it's just 5%', which is something I say all the time, is true in most cases, but the personal experience due to many factors (some of which mentioned above) can make that 5% seem like a lot more. Hell my gf is a teacher and she was grading an essay about a particular muslim ethnic group in my country, who number 2.3% or so. The girl had gotten that figure wrong by an order of magnitude, she cited more than 20%. My gf was frustrated that she could get it so wrong (i.e. that such a large mistake didn't ring any bells for her to recheck her sources), until I showed her that in our city, for people of that kids' age, the number is actually quite close to 20%, and even higher in certain neighbourhoods, and that it was perfectly normal for that wrongful 20%+ figure not to be a red flag for her.
Anyway as to your question, I'm sorry I don't know what the exact figures are in Malmo. Just that 'arabs' is probably not the right statistic to look up, Muslims is an improvement, that they're 5%, but that I can imagine it's much higher in cities, and that the negative 'experience/feeling' of this percentage can be even greater than that due to various demographic factors.
Lastly, beware that, as you obviously know, statistics can be misleading. Social issues particularly are sensitive to definitions. Is a 3rd-generation migrant, whose parents both were both in Sweden, lived there for 50 years and have a 20 year old child, still seen as a foreigner? Is a brit who lives in Sweden included in the figures, making the natives a minority? etc. This stuff matters a lot. In the Netherlands for example, the king and queen are both foreigners on the basis of definitions used in the Netherlands, as are their children. In fact the royal family's children are specified further, as being 'non-western foreigners' (i.e. not say from Europe or the US, but rather from say Africa, Asia or South America). In any city they live, they're reducing the percentage of the native white population and increasing the number of non-western foreigners, which may be a scary conclusion to many, even though nobody has a problem with these kids [0]. Yet this is the official definition used in government, academia, media, education etc. So if someone says 'x is becoming a minority', well consider carefully on the basis of which definitions that's true.
Regarding the racist tendencies in the Netherlands: take heart, not everybody shares them. Wilders may be a very loud mouthed politician but he still represents just a minority.
