Anything salty goes with beer. Mixed nuts, pretzels, etc etc, and they also make people thirsty, which can only be good for business. Chocolate goes good with certain liquors (I know I like it with whiskey), but if you plan on selling actual food in a pub, things like garlic fries, chicken wings, potato skins and other finger foods are quite popular in the States. It should obviously be catered to wherever you're doing it, so why not check out some local spots that seem to have large crowds? If people are eating there, see what they're eating.
ﾅｽﾃｰ/ﾆ池ﾂーﾆ停?ｹ窶堙個催ｦ(SAKAMA)ﾂ ﾂ：ﾂ Something to nibble on while drinking of liquor / beer beer
ﾅ?`窶堙固ｽﾃｭ (KAKI NO TANE)
OR ﾅ?`ﾆ痴ﾂー(KAKI Pi)
These tiny spicy senbei crackers are the same size and shape as persimmon seeds, and indeed, the name "Kaki-no-Tane" literally means "persimmon seed" in Japanese. This pack contains kaki-no-tane only, and is just what the doctor ordered for people who are devoted to kaki-no-tane. Goes especially well with beer and whiskey. http://confectionery.jp/ekasi.php?code=4901313027851