My grandmothers wood stove has a cover that is multiple sizes and the small one is about that size. You can remove the small center cover a second ring shaped cover or all three covers. I guess this was so that you could use different sizes of pots on them.
so this is a stove with the smallest that i could find. my find is half the size of the small one. but it was a good guess. im stumped on what it is. im going to try and clean it this weekend. and i will post more pics. thanks for all the replys