Silverplate tray with only the letter E as a mark

[roundman]

I am a volunteer at a charity thrift shop and we receive donations from estates. I try to identify the items to maximize the value when they are sold, especially to dealers who regularly visit seeking underpriced objects. I always check this website and other websites before posting my query here.

I have this 9” silver plate tray and the only mark on the underside is an embossed single serif-font “E”. Any ideas on its source?