I believe the rule is any food that is perfect for eating on the road while you drive 45min from your first job, to your second part time night shift job. All of that kind of food doesn't exist in Europe or at least isn't popular for some reason.
Depends on the burrito. If it looks small enough that I can finish it without it starting to fall apart in my hands, then I probably can eat it that way. Most of the burritos in the local texmex places though? Yuge.