As nouns the difference between tray and case
is that
tray is (obsolete) trouble; annoyance; anger or
tray can be a small, typically rectangular or round, flat, rigid object upon which things are carried while
case is (
label) abstract feature of a noun phrase that determines its function in a sentence, such as a grammatical case and a position.
As a verb tray
is (obsolete) to grieve; annoy or
tray can be to place items on a tray or
tray can be (obsolete) to betray.