One option if you want to go there is pork rinds. There are also nuts, jerky, and laughing cow wedges or babybels (can go days without fridge). Unfortunately, like bars, these can all end up being trigger foods for some people. This is especially true if they add savory flavors (like BBQ rinds, wasabi nuts or terayaki jerky).
You can get canned shrimp as well as the tuna/chicken/ham. Some cans come with pull-tabs so you won't need a can opener. You might also consider keeping something like a small jar of oil-cured olives on hand and take home any leftovers.
I hope you find some options that work for you.
Deborah: Hoping to earn the user name NoYoyoMa (maintenance start: 6/30/2014)