Nephi, the first author in the Book of Mormon, began the record by introducing himself, then submitting his credentials in order to help validate the authenticity of his account. (Nephi 1: 2 – “Yea, I make a record in the language of my father, which consists of the learning of the Jews and the language of the Egyptians.”)
When Nephi’s father Lehi and his family left Jerusalem for the “Promised Land”, they carried with them records of the Jews. They were the plates of brass, which Nephi got from Laban. These plates contained the Old Testament Bible record up to Jermiah and a lot more. Nephi and the following prophets followed the “learning of the Jews” in the Book of Mormon narrative. In other words, the Book of Mormon format follows Hebrew traditions.