We have ham at Christmas. Now I've got this weird feeling I've been doing something that's a faux pas but I can't find a reference on the Internet anywhere. Why will people complain about the ham sandwiches?
Jews do not eat ham. They also don't celebrate Christmas. Having an office Christmas party and serving mostly ham is a great way to drive home exclusion. Or e.g. demanding people work late Fridays. Observant Jews absolutely, positively have to get home by sundown on Friday.
Having kosher food doesn't mean we can't have ham. People eat other things at Christmas anyway. And calling it a holiday party doesn't take anything away from anyone.
Well, isn't the simplest solution for them to not eat the ham sandwich or not attend a Christmas party if it's such a big problem for them?
There will always be someone offended by anything you do.
I'm atheist and have no problem celebrating Christmas or Diwali or whatever with my colleagues from work.
I guess it entirely depends on the type of person you are.