@minxomat Yes, not necessarily. However in the case of Chrome I think it has some really fancy rendering engine that (on Linux at least) when running in each individual process seems to take a lot of memory.
I have chrome, a terminal, libreoffice and thunderbird open and that's 4 gigs in total.
And closing thunderbird and libreoffice keeps it still at about 4 gigs so.
I frequently use VMWare to virtualize OSX on my windows laptop. So it needs at least 16G of RAM. My linux netbook (runs arch linux) has 512M of RAM and runs chromium with multiple tabs just fine :D
One statistic they do exhibit is that the more times the same message has been posted in chat, the more likely an instance of that message is to get starred.