[Dort]

I assume you are not using Excel 2003 on your 16GB machine. May I ask which version of MS Office you are using?

If I have to believe this[1] thread, then Office 365 is now an Electron app, which would explain the slowness.

[1] https://news.ycombinator.com/item?id=17300893

[xbar]

I most live on Macs. But for big spreadsheets, my Microsoft Excel 2010 on a modern Windows PC is blazing fast to open, load, operate and calculate. Sub-400ms and 8.4MB RAM to launch.

Sadly, support ended October of 2020, so it's time to find something else before too long. It is not going to be contemporary Office.

[radmuzom]

I am using Office 2016 Professional (Microsoft does give it away at dirt cheap prices to many corporate employees). Desktop version installed using an .exe.