Thank you for contacting Mearto with your appraisal inquiry.

It is a beautiful antique silverplated tray. Such antique trays are being offered at auction on a regular basis.
The tray is a large tray with elaborate decoration on the front and on the edges. This particular style of decoration was often seen in both Europe and USA during the first part of the 1900s. The material it is made on is like you describe silver on copper. Also known as silverplate - this too was often used and in particular on very large items like your tray.
The tray appears to be in good condition which affects the appraisal in a positive direction.

I cannot see the marks clearly enough for me to say who and where it was made but this particular type of household item was popular worldwide in the wealthy houses during the first half of the 1900s.

The estimate provided is for a well-advertised specialised online silver auction, where I believe the serving tray has the best chance of realising its fullest potential. However, there is no measurement for the sentimental value you might attach to the silverplated tray. Retail "asking prices" can be higher and vary.

Please let me know if you have any additional questions. I’m happy to help.
Thank you