That’s a weird looking serving dish
The person who posted this image allegedly found this old stone piece while cleaning out their attic. Not knowing what it was, the OP didn’t want to toss it away out of fear that it might fetch a pretty penny. So, he did what any person would do in their situation: ask Reddit.
According to a few users, this is a cloth seal, which was once attached to bales of old cloth during the manufacturing process. This cloth seal might have been used in the late 1500s, but without speaking to The Beard from Pawn Stars, there’s no way to find out for sure.