One time in a Toastmasters meeting someone brought a bag of the most obscure objects in for Table Topics and, when we picked an item out of the bag (I don't think we were allowed to look), we had to describe what it is, and I believe, where we got it from.
That exercise was evil!
(Although I have participated in similar Table Topics segments that were less harsh.)
If you live near nature, what you could do is get a whole lot of things you find there--rocks, things from trees, maybe a flower, a stick, leaves, etc--and hand people one of these objects and ask them to describe what the object reminds them of--either a story from their own life experience, or a memory of maybe something they've seen on TV, or read about.
Whenever I did Table Topics, I always designed it with a goal in mind--i.e. what particular skill did I want to help them to improve with the exercise? Usually I'd decide that first, since it made it easier for me to figure out what type of Table Topics questions or props would test and train those particular "muscles."