I have a TEFL certificate (Teacher of English as a Second Language) and I'm a native speaker and avid reader -- and this was the first time I ever encountered "rubber" as a synonym for "eraser". The benefit of the latter term is it's unambiguous and easily understood.
I have an even weirder example from Russian language: file, folder and pocket are 3 out of dozen different words being used to describe a plastic envelope for documents in various regions and people don't understand each other. I remember only one more.