You could, but it’s not something I’d recommend. Beverage coolers are made for drinks, not food. They keep a steady chill, usually between 35°F and 45°F (1.5–7°C), which works great for cans and bottles — but it’s a bit too warm for things like meat, dairy, or leftovers.
Over the years, I’ve seen people try to use them like a mini fridge, and the food just doesn’t keep well. The air inside a beverage cooler moves more to keep temperature even, which actually dries food out faster.
If you just want to keep snacks, fruit, or bottled water cool for a short time, that’s fine. But for anything that spoils easily, you’ll want to stick with a regular refrigerator. The cooler’s really meant to keep drinks ready to serve, not to preserve food.