As I have said about other Wodehouse public school stories, there are always negative reviews of those books here in goodreads, because of a problem of expectations. Most people reading these books nowadays are fans of Wodehouse's comic fiction, and when they find out that these early works are mostly not comedies they are disappointed. There are certainly signs of the author's irony and wit, but these were written for a different market and in a genre with different conventions.
Tales of St. Austin's is not a novel, but a collection of short stories and a few humorous essays that were published in fiction magazines for boys between 1901 and 1903. They are about the misadventures of different boys attending a public boarding school called St. Austin (the same one where his book The Pothunters was set). Some of the characters appear in several stories here and in that novel.
Even though he builds on the same genre tradition and conventions, you can see the differences with the pioneers of the genre, because Wodehouse is not interested in moralizing. The characters here are boys who want to get out of inconvenient exams or get away with breaking the rules. Some of them are cads and some are likable, but they mostly correspond with the archetypes expected in the genre; do not expect deep characterization in these short stories. But they are well-written, and I found them entertaining and funny in their own way.
Although these Wodehouse school stories are always pleasant for me to read, one thing where he is less to my taste than other contemporary writers of school stories is that he doesn't really do the underdog story. You know, the story where the main character is unfairly accused of something or who has to surmount serious difficulties to get something he wants or earn the respect of his peers, and comes through because of his pluck and strength of will. I always enjoy that kind of stories where you can cheer for the main character, but Wodehouse tends to look at this setting with fond amusement, rather than as a source of epic drama. Possibly that's why my favorite so far among his school books is The White Feather, where he follows that underdog trope very well. (I haven't read Mike yet, though, the one where he introduces his character Psmith, and which is his most famous school story).
After several short stories and a long one, the book ends with a few humorous essays, where he deals with subjects like the school work these boys did (heavy on Latin and Greek translations), with cricket and even with the classic novel that basically created this genre (Tom Brown's School Days, by Thomas Hughes). Wodehouse is witty and funny in these, but it may be tough for modern readers to appreciate if they are not familiar with the subject.