There likely would have been some local Italic languages that hadn’t died out to Latin and some amount of international/interprovincial trade going through, but more likely is that these are just decorative. Some Roman shops did definitely have signs, but even those were sometimes just symbolic - literacy was high in Roman cities, but still very far from universal - especially for any folk from the rural surrounds passing through!

Funny enough, though you can’t see it here, on this counter there’s some graffiti scrawled on one of the paintings