W. Somerset Maugham's story "The Luncheon" is a humorous little tale about an extremely expensive lunch, but it hints at a deeper significance.
Let's begin by recalling what happens in the story. The narrator has just met an old acquaintance, and she reminds him of a luncheon they once shared. He certainly has not forgotten! At the time, twenty years before, he was a poor writer in Paris "earning barely enough money to keep body and soul together" but somehow managing to get by.
In the flashback, the narrator's acquaintance has read one of his books and wants to meet him, so he agrees to lunch at the expensive Foyot's. He doesn't have much money but thinks that if he is economical, he can manage a special treat. His "friend," however, has something else in mind. Despite protesting that she never eats anything much for luncheon, just one thing only, she proceeds to order the most expensive things on the menu while the narrator settles for a measly mutton chop (which she berates him for eating, saying that it is too heavy for luncheon). He barely has enough money to pay the bill and has to leave a very small tip. His "friend" looks askance at that and thinks him "mean." As they leave the restaurant, the narrator wonders how he is going to live for the rest of the month, for he has spent everything he has on that "little lunch."
Clearly the narrator's "friend" has taken advantage of him. She has expensive tastes and probably enough money to have purchased her own luncheon (for she is traveling on the continent). She flatters the narrator significantly to make him willing to treat her and then acts like she hasn't ordered anything much at all, even as she scolds him for ordering too much.
Maugham is making a larger point here. Upper-class people like the "friend" sometimes take advantage of lower-class people, getting them to do and pay for all kinds of things they could easily have done or paid for themselves. Business owners often exploit workers, for instance, paying them little, making them work long hours, and then acting like they've done the best thing in the world by giving them a job. The workers dare not complain. The lower classes also often share more heavily in the tax burden, paying for luxuries that the upper classes want yet don't care to purchase for themselves. Maugham makes this little luncheon a symbol of some major exploitation.