Oh boy, what can I say! Been there, done that! You've gotten some great advice with the candy dish and the pictures of your kitties.

I have been told that I'm hard to "get to know" and to some degree it's true. When new people come aboard, I do welcome them, but don't go out of my way at first to really get to know them. I usually let them adjust to the job for a couple of months before engaging in "social" conversations. Hearing what you have said, maybe that's the wrong thing to do and I thank you for your perspective.

It's a good thing (sorry, not trying to be Martha Stewart... ) that you took the initiative about lunch. That shows others that you would like to spend time with them outside of the work environment. Don't feel bad that they didn't invite you back. Heck, I've got some great coworkers and we lunch together maybe every 3 or 4 months.

Hang in there and give it time.