I agree with Onxy. I used to take a lot. Now i realise less is better for all of us! I take one or two things each for the girls now. At the airport (or toy stores) you can buy those books that have a 'magic marker' It's clear, so no mess and as they draw on the page the color magically appears. I love them as there is only one pen for every color and no drawing on things!
My DD's love a sticker book.
Other things we do is make puppets out of the spew bags, play eye-spy with the dutyfree shopping mag and inflight mag. (But 'eye-spy something green', not 'beginning with' iykwim?) The kids love to put the headphones on and have a dance to the music.

What you have sounds like heaps.