Much of the humor in Somerset Maugham's short story "The Luncheon" derives from the fact that the narrator is trying to appear sophisticated, urbane, and gallant, whereas he really can't afford to be entertaining this woman in such an expensive restaurant as Foyot's. He feels relieved initially because she tells him, "I never eat anything for luncheon," and then he is appalled when she orders some of the most expensive items the place has to offer. Maugham describes the situation in just a few words:
Foyot's is a restaurant at which the French senators eat and it was so far beyond my means that I had never even thought of going there. But I was flattered and I was too young to have learned to say no to a woman.
Maugham was born in Paris and was thoroughly familiar with French literature. His stories seem influenced by those of the great Guy De Maupassant, who had learned from his uncle Gustave Flaubert to appeal to all of the reader's senses in order to create effective scenes. In "The Luncheon," Maugham has an excellent opportunity to appeal to the senses of smell and taste. For example:
The asparagus appeared. They were enormous, succulent and appetizing. The smell of the melted butter tickled my nostrils as the nostrils of Jehovah were tickled by the burned offerings of the virtuous Semites.
The narrator is vicariously savoring all his guest's expensive items-- but he has to keep pretending that he only wants a mutton chop and a glass of water. He is suffering in at least two separate ways: he is watching the woman enjoy all the things he cannot enjoy himself, and at the same time he is getting increasingly anxious about paying the bill.
Although his guest keeps repeating that she never eats anything for luncheon, he watches her eat salmon, caviare, asparagus, ice cream, and a peach. She also drinks a half-bottle of champagne and a cup of coffee. By the time the narrator pays the bill he is flat broke and, as he says:
I had a whole month before me and not a penny in my pocket.
The narrator is telling about this incident some twenty years after it occurred. It was obviously a painful ordeal when he went through it, but he is now able to see the humor in the situation. Humor and irony are characteristics of Maugham's personality and are to be found in nearly all his fiction and nonfiction. He also observes that it gives him a sense of revenge knowing that:
Today she weighs twenty-one stone.
It should not be surprising that a woman with such an appetite would become obese in twenty years. A "stone" is a British unit of measure equivalent to fourteen pounds, so the woman would weigh very close to three hundred pounds.