If there's someone to sit with i will. I don't really enjoy it neither do i hate it, i just feel that it would be rude not to sit with someone i know. It's my summer job and i don't know yet if i will be continue working there, so i also feel like i have to be really nice and sociable (and of course do my job well) to give a good impression and hopefully to get to continue there in the fall..
I thought I was weird for wanting to lunch alone but maybe not after reading your posts! I am friendly to all my co-workers but certainly dont see them as freinds and only interact on a social level if I absolutely have to. I think people might see me as weird and shy because of this but I hate eating in front of people commenting on what you're eating!
I work retail so it's not often that I get to take lunch at the same time as anyone from my department because we can only have one person on lunch at a time and we have to take it i turns. However most people at my workplace will eat at the table in the breakroom and there is nearly always someone else in there so I will usually chat with a colleague from another department.