What is the best way to entertain yourself while travelling? (And what food is best to bring?)

This Sunday I’ll be travelling by train for at least 36 hours (and likely some 9 hours more if I’m just a little bit unlucky with transfers)—all by myself.

Although there are two nights included in which I’ll hopefully be able to find some sleep, I need to find a way to entertain myself and not go crazy – reading books only stays fun for a while.

Furthermore I need to bring food with me, preferably something that tastes well and does not go bad in this time period, is easy to bring along and consume and does not smell.