James Gatz' schedule as a young boy reveals several things to the reader. First, it reveals that he had an 8 hour a day credible job. This is something we don't see in the book. Second, it reveals that before and after work, he made the effort to improve himself mentally and physically. Finally, it demonstrated he had resolves which meant improving himself morally. He specifically chose not to smoke or chew. He wanted to improve his treatment of his parents. He wanted to have good hygiene and save his money.
These resolves certainly display the man we see on the outside when we meet Jay Gatsby, but the man on the inside must be different.
There's a certain poignancy in the young James Gatz's schedule. It places him in an old-fashioned American tradition of self-improvement, bringing to mind figures such as George Washington and Benjamin Franklin. It also reminds us of the Protestant examination of conscience that we connect with the early settlers of our continent, the Puritans and pilgrims. This is especially so in Gatz's list of "resolves": "No more smokeing [sic] or chewing ... Be better to parents." In its staidness, the schedule jars us, showing us a side of Gatsby different from the lavish host of wild parties flowing with illegal liquor, and different as well from the Gatsby with ties to criminal enterprises. If Gatsby is a representative of the American Dream, both corrupted and pure, the schedule is a window into his purer side. It connects us with the puritanical Gatsby beneath the smooth, genial surface of the man-about-town in the pink suits. This is the same Gatsby who is the only person at his parties who doesn't drink, the Gatsby who goes all summer without ever once using his glamorous pool.
The schedule also reveals young James' ambition, as his father so rightfully points out. It's the schedule of a person determined to get ahead. He wants to stick to a rigid schedule, to read self-improving books, and to "practice elocution, poise and how to attain it." How much of this he does or doesn't do is part of the mystery of who he is: he hasn't read the books in his library, as we know from the uncut pages, but he has attained a certain poise. Confronted with this raw reality of James Gatz, Nick retreats into satire, a weak joke. The father looks eagerly at Nick, and Nick can only muster, "I think he rather expected me to copy down the list for my own use." In the end, though, Nick's admiration will win out.