"Tom's Diner" is a song about the mundanity of daily life and the various interactions that one may have while sitting at a diner. The lyrics paint a picture of a woman sitting alone at a diner counter, observing and reflecting on the people and events around her. Throughout the song, she is lost in thought, listening to the sound of the rain and thinking of a past memory.

The chorus of the song, which consists only of "doo-doo-doo-doo" sounds, serves as a representation of the ambient noise of the diner. It adds to the overall atmosphere of the song, emphasizing the sense of banality that the speaker is experiencing.

The first verse introduces the speaker as she waits for her coffee and remarks on how the man behind the counter fills it only halfway. She observes him looking out the window, and the song sets the tone for the rest of the narrative.

In the second verse, the speaker notices a couple come in and exchange greetings with the man behind the counter. She pretends not to see them and pours her milk. This interaction highlights the speaker's desire for privacy and solitude.

In the third verse, the speaker reads a newspaper article about an actor who died while drinking. She then turns to the horoscope and comical pages, giving a glimpse into her personal interests. She feels like she is being watched and raises her head, indicating that she is alert and aware of her surroundings.

The fourth verse introduces a woman who is looking inside, perhaps looking at the speaker. However, the woman is merely looking at her own reflection in the window. The speaker tries to ignore her as the woman fixes her appearance.

The fifth verse describes the rain continuing as the speaker listens to the bells of the cathedral. She is thinking of someone and their voice, indicating a yearning for companionship.

In the final verse, the speaker finishes her coffee and heads off to catch a train. The repetition of the chorus at the end of the song gives the impression that she will continue with her routine, day in and day out, as she reflects on the monotony of her life.