I claim the ornamental design for food container assembly, as shown and described.
FIG. 1 is a top, left and rear perspective view of a food container assembly showing my new design, the food container assembly including a compartmentalized main tray and a removable inner container covered by a transparent lid;
FIG. 2 is an enlarged left side elevational view thereof;
FIG. 3 is an enlarged right side elevational view thereof;
FIG. 4 is an enlarged top plan view thereof;
FIG. 5 is an enlarged bottom plan view thereof;
FIG. 6 is an enlarged front elevational view thereof;
FIG. 7 is an enlarged rear elevational view thereof; and,
FIG. 8 is a top perspective view of the food container assembly of FIG. 1 without the lid, and with the removable inner container placed next to the main tray.