When we camp, we are seriously starving at the end of the day. We go hard all day and I'm sure you will too. You need some substantial food! lol I don't feel comfortable keeping anything egg or mayonaise based in a cooler. Especially for 3 days! My Suggestion - check for a state park or even a roadside park with picnic grounds and bbq pit in the area to go make some burgers! Take one or 2 of the other familys you never get to see and want to spend a little more individual time with. Or it may be good just to go with your little family to decompress from being around all those other people. Time to reconnect with each other. And what's camping without a campfire, and smores!
You can take trail mix, salami and crackers, dried fruits(raisins, apricots), beef jerky, granola bars, dried creal, Pita bread, flatbread or tortillas (doesn't squish or dry out as fast as sliced loaf bread) foil pouches of tuna or chicken (Chicken-of-the-Sea, BumbleBee, etc.) These are great for camping meals -- tastier and not as messy as canned. The smoked salmon, teriyaki salmon and lemon-pepper marinated tuna are very good. Great in flatbread for sandwiches.