A small plate or stand that you put a hot serving dish on is called a trivet. Your famous chicken noodle casserole might need to rest on a trivet so you don't burn your kitchen table.
Anything placed on a table to protect it from a hot pan can be called a trivet. If you forget to use a trivet under a pot of chili, your table might end up with a big scorch mark. The original meaning of trivet was "three-legged stand," especially one used under a cooking pot in a wood stove or over an open fire. It probably comes from the Latin word tripedem, "three-footed," from tri, "three," and pes, "foot."