Vintage cast iron string holder, bee hive shape. It's not marked at all that I could see, though it's showing wear and age.
It's shown holding a fine hemp cord (not included). It could easily hold a thicker twine or yarn, it'll hold a ball about 3 1/2" x 3 1/2" comfortably.
The has a pleasingly heavy weight, it'll stay where you put it. Great for a gift wrapping or packaging table, a kitchen counter, a potting bench or tool bench.