From what I can gather from larger people on Twitter, this is usually not the case. I follow Roxane Gay on Twitter and she is forever calling out different venues where the chairs do not work for her body, flight attendants who do not know how to handle a fat passenger bringing their own seatbelt extenders, venues where there are not stairs for her to get on the stage for a reading, etc. Thin, able-bodied people don't know how to handle people with unruly bodies. It never occured to the hostess that Kate could not fit into the booth until Kate spelled it out to her. And most likely, that information went in one ear and out the other. Toby could have made the reservation at the restaurant, specifically asked for a table not a booth, and they still could have ended up in the situation shown.