Based on the images and without being able to see the marking, what this piece appears to be is a late 18th to early 19th Century Chinese Armorial hot water plate. Armorial Plates were first made to order for export to Western markets Circa 1710, the Coat of Arms being that of the family that ordered them. They remained a popular item and status symbol with wealthy British families into the early 1900's.
Without physically examining them, or having no provenance to trace, dating them is difficult. That said, most comparable to this one are late 18th Century and often list in the $300.00- $500.00 range where they most often change hands, at auction. Values can be much higher if a provenance can be traced to a famous family.