The author's purpose is to entertain.
Like with any work of fiction the author's sole purpose is to entertain the reader. Le Morte d'Arthur is a book about the legends of King Arthur and his knights of the round table. It is based on stories of King Arthur and a poem by Lord Alfred Tennyson. Even though the legend of Arthur is still to this day debated as to whether he ever existed or not, Le Morte d'Arthur is a work of fiction and therefore is meant to entertain.