The first one has nice bright colors, and the light looks bright and clean. The rest have somewhat dull light, to the point of looking slightly underexposed. You could probably improve them by brightening them with a curves adjustment, and adjusting color temperature and saturation to taste.
The two of the steam table bins look ghastly, mainly because steam table bins are associated with gloppy bad food for many of us. The one with the food handler's hand in the frame is likely not very appealing. It looks like a school cafeteria or something. These are potentially interesting documentary shots, but they don't make me want to eat the food.