formal  ... wear some sort of dress; but make sure you can make it more casual looking, as an option, if he doesn't dress to match.   \n\nAs for the table setting.... when in doubt go 50-50.  Set the majority of it before (silverware, glassware, centre piece.)  Then have him help with the plates ... Unless you want to PRESENT your food.  \n\nIt's up to you.