This is a Mikasa Courtney 9380 chop plate or round platter. It is 12 1/4" wide. This pattern was produced in 1958 and is now discontinued. It is a design with green and grey leaves and a turquoise and brown lattice around the rim. The trim is platinum. There are a few utensil marks and a bit of wear to the platinum trim on the outer edge.
Mikasa Courtney 9380 Chop Plate Round Platter