Korean Goryeo (918 to 1392) celadon dish

I bought it from a Japanese dealer who didn't know much about the provenance. The Goryeo dynasty I believe it was made in, due to the technique applied. Considering the age, it evidenced the achievement of Korean craftsmanship. The glaze is silky smooth and blinding shining, even the best Chinese glaze at that time can't compete. Korean also developed unique to have inlaid patterns on ceramic. The white lines on this dish is inlaid and rises a little bit above the surface. The bottom is coated too, and 3 uncovered spots shows how was this piece underpinned and fired in kiln.

Except the modern copies, this kind of Korean celadon wares were made in Goryeo period for autocratic households only, and discontinued. What a shame. The things I don't know is what is it for? A dish for kimchi? maybe.