unidentified pottery piece, shape and signature

Yesterday I discovered a round flat piece of pottery on a garage sale. The diameter is 7 inch. It has a uni olor glaced surface except of the base which is signed. I try to figure it out what it actually is. It must be a flat vase. It has many tiny wholes on top smaller then a fingr tip, just enough the size of a flower stalk. It would be easy to say it's origin if I could read the signature. Something like 'Pi Bing' 'Ri Big'... no idea. Amybody knows what it means? Thanks for your help.