Plane food isn't usually filling unless you're coming higher class and long flight.... and they are including a meal. It's usually just snacks. Most places either have peanuts or crackers
You can either do tablet or you can do something like a busy book or board to keep kid busy
I’m also flying to America with my 2 year old in 2 weeks I’m taking plenty of snacks and toys I’m taking her busy book, colouring book, stickers, pop it toy, toy tablet and some books I’m also going to be downloading lots of shows/movies on my iPad