Hello and welcome to the forum.
Your tray is silverplated.
Next to Christofle in France, Elkington is one of the most popular silverplaters with collectors.
That set of marks was used from 1865 through 1897.
Can't identify the date letter. Elkington date letters cause a lot of problems.
In my opinion it's best to get a general time frame from the whole set of marks.
Check here:
viewtopic.php?p=35988#35988
Pat.