I have found if I put one single food/buying stall on the lot it will be staffed, but if I put 2 or 3, none of them will be staffed. With the vendors, no matter how many tables I put out only 3 of them will be vendor staffed and the items on the tables will be left on the tables and sill there when another set of vendors come the next day and add inventory. Everyone that goes on lot will use a coffee machine, tea pot, microwave, sink, oven, fridge, or vending machine. They will also occasionally use a grill. I've not seen anyone buy anything from the vendor or stalls though unless I'm controlling them.
