A touchscreen gadget the size of a Moleskine notebook sits propped up at the end of the table at Uno Chicago Grill. It’s not on every table, but certain returning customers ask to be seated where they’re placed. During the busy lunch service at Au Bon Pain, employees greet customers and take customized sandwich orders using iPads. While customers wait for their sandwiches to be made, they can purchase a bowl of soup or order a freshly tossed salad.