Items Brought Back From WW II European Theatre.

These two items were in a duffle bag of items my father returned with from the European Theatre after WW II. I am not a military collector, so my knowledge in this area is limited.
The cup seemed rather large to be a regular drinking cup, but I could be wrong. I thought the square pans were mess trays, but seemed too small. The two pans actually come clamped together and you unclamp them to make two identical pans.
As I have previously shared, my father was a Normandy survivor. He was Exectutive Officer of the First Battery of heavy artillery(155 mm gun), 190th Field Artillary Battalion, Fifth Corps, First Army. He passed away in 1992. Sadly, pretty soon they will all be gone.
Thank you.