A hard reset, as mentioned is a good starting point....after closing any open apps. If this doesn't help, visit a genius. I've yet to have an app crash on my mini. I've owned it since launch and easily use it three hours a day. You might have an actual issue. Hardware or otherwise. If the behaviors persist, bring it in and have them test it.
I don't usually have 7 tabs open...but I do use Chrome often, and usually have at least three or four. It's never crashed on me
Good luck...buy realize this isn't typical behavior. May have a lemon on your hands