I guess I'm lazy bc often when we eat out, I just forgo any expectations of eating civilized. As in, I bring just disposible stick-on place mats to use as a plate, and order him food that can be cut to bite size by me that he can eat with his hands. No plates, bowls or silverware. When he was under 18 months, we did a sippy with a tether, but now if I forget the sippy I don't sweat it. I just go with the kids cup the restaurant supplies. He still can't be trusted not to squeeze the snot out of a juice or paper cup, so I keep it out of reach, and hold it for him when he asks for a sip or I deem he should be drinking more. I figure I'm not compromising his development in eating skills for doing this a few meals a week, or heck, even one vacation. I probably will pack his thermos sippy of cold water for the park, which I will just give to him at meals. I'll just wash those in the room at the end of the day.
So ultimately all I need is a disposible place mat, maybe a sippy, and wipes for his hands. And of course any snacks I bring into the park in case the food is taking too long.
As for bibs, either bring them or bring a change of clothing. Unfortunately, disposible bibs got shredded by our DS, so they were a no-go for us.
Your one issue might be non-pouch yogurts, applesauce. You can always snag some disposible spoons from your resort or a TS restaurant, or just load a regular spoon and hand it to them. Though I know the latter is more work.