Looks like an aspic to me. Ham, olives, and vegetables along with some fruit. Kiwi is an interesting choice , because the fruit has a protein-eating enzyme that affects the way gelatin solidifies. Usually they contain prunes or raisins.
Fucking hell, I thought those were mussels in between the olives and I had to check it online. It's not. They're oysters ! This is no mere crime, this is an aggravated assault. Post of the year.
It's an aspic, which is like the savoury version of fruit and Jello. Even people who liked them would probably agree that the kiwi and oyster? do not belong. The rest is entirely believable as an aspic that people would have made and eaten in the US around the 1950s to 1970s. I've never tried one myself, but I think I'd prefer to keep it that way.