Foil food trays are freezer safe.
You can freeze the food that is in the foil food trays by just placing the foil trays directly into the freezer.
There's no need to cover the foil tray with any additional plastic.
If you have lids for the foil trays just place the lids on the foil trays and then place the foil trays directly into the freezer.
The lids and foil trays will be just fine in the freezer.
I freeze casseroles and other dishes in the freezer using the foil trays and they are just fine.
The foil is freezer safe.
If you have no lids for the foil trays then you can wrap the foil tray in some plastic Saran wrap or put another foil tray on top of the first foil tray.