Wow, for all the times I've gone to Seaworld, I never knew they had any restrictions on the food you can bring into the park. I've always brought about 6 bottles of water, snacks like cookies and crackers(full size boxes), candy, granola bars, beef jerky, etc. I think I've even brought in a whole sleeve of Thomas' bagels. I only pack what I can in a backpack, so it's not like I'm rolling in a cooler or anything, so maybe that's why they've never stopped me. I suppose it's technically not sandwich supplies as I don't bring deli meats or lettuce.
I would think lunchables are fine as long as you're not bringing a dozen or so in with you. To me, that's not even enough food to really consider lunch. More like a snack. I would take the chance as the parking lot is walkable, within about 5 minutes if you really need to bring the lunchables back to the car.
