I traveled by train for 13 hours with my 18 month old.
I loved the wallet idea, it kept him busy for a while.
-books, book and more books
-toys
-colouring
-snacks
He was also kept busy for a very long time just using thing on the train.
-bushing buttons
-pulling things
-walking
-opening doors
-playing with the trays on the seat
-turning on and off the lights
-touching different textures on different thing on the train
-looking out the window