What does a tray stamped with silver with an a under it mean?

A tray stamped with "silver" and an "A" typically indicates that the piece is made of silver-plated material, rather than solid silver. The "A" could represent a manufacturer’s mark or a specific standard of plating. It's important to research the context of the stamp, as different manufacturers and regions may have varying marking systems. Always consider consulting a silver expert or reference guide for precise identification.