It's a patch, a veneered Victory-style marble, at least. I think old-timers may have referred to them as "Spots" but that term is no longer used as far as I know. It's probably older than the more common Victorys.
I think it might be a variation of "Spin Jenny", which, as far as I understand, involved spinning a wooden dreidle-like top to knock mibs into the point holes.