I have a colleague who doesn't chit chat during lunch. Only talk about work. When talk about other things, at most she will smile and no comment. With her around, the entire lunch hour is quiet. How to exclude her from our lunch group without hurting her?
Excluding is a pretty mean thing to do in my opinion. Instead, why don't you try and institute a no-shop-talk policy over lunch, or better yet, chat to her about why you don't like to talk shop. Just let people know that it's lunch and that you don't want to talk about work, and you'll find you can be inclusive and get everything you want out of it.
You're asking to deliberately exclude someone, and that can only be a bad thing. Try being inclusive, instead of exclusive, and try (if there are issues) to resolve them instead of just blocking others out.
The reason people like to talk about work is because that's 100% what everyone at the table has in common with each other. Try to perhaps engage her on conversations not about work, find a common ground and talk about that instead.
Your lunch time sounds like a clique in high school. If she's not participating in any conversation besides those about work, and she's merely staying quiet, then I don't see a reason for excluding her.
It's not a good idea to burn bridges with co-workers, as networking is more important than a lunch time club.
1) If you're keen on burning bridges with your colleagues, then by all means, exclude her right away without hard feelings from your side. I strongly recommend otherwise, though.
2) She probably has her reasons not to chit-chat around you guys: most likely she's not comfortable (and thus has no idea what to talk about). If you really want to talk about non-work stuff, you will have to try her to open up. This can be extremely difficult if she's an introvert. However, even introverts will open up when they're comfortable. Ask her what she did last weekend, or is doing next weekend. Ask her if she made plans for the summer holidays. Ask her if she ever been to place-x. There's so many options really.
3) If you don't want to be around her during lunch, you can also "exclude" yourself. Go to a local bakery or coffeeshop during your break, go have lunch in a park. This is probably not what you're looking for, though, so I would say try to go with #2.
Tell her that you (and I assume other coworkers) prefer to not talk about work over lunch, and that if she must, then you will lunch without her.
There is no harm in honesty - the passive-aggressive stance of trying to find a way to exclude her without telling her will lead to much more issues. She may not even know you have a problem with it.