It's basically just a reference to getting in the next batch of diners. A restaurant may need to turn each table 3 times in an evening to make bank (profit).
While this may have changed, for a long time it was rather unique to the US. I worked for a restaurant owner from Sicily 30 years ago and he said the concept of "grabbing" dinner on the way to another event was not a common practice in Europe where the dinner is the event and people tend to linger. To this day his family has a great restaurant which is white tablecloth fine dining on one side and more of a casual experience in the bar and on the patio.
That whole rushing diners has gotten so bad that I actually saw something on the tube about dining etiquette dictating we should not tie up tables and servers doing things like (jokingly) giving a table a parking ticket. I found it galling to be told we are being rude by not allowing ourselves to be rushed out the door!
Equal rights for others does not mean fewer rights for you. It's not pie.
"I prefer someone who burns the flag and then wraps themselves up in the Constitution over someone who burns the Constitution and then wraps themselves up in the flag." -Molly Ivins
Never try to teach a pig to sing. It's a waste of your time and it really annoys the pig.