When Nephi has obtained the brass plates, he describes what they contain in 1 Nephi 5
11 And he beheld that they did contain the five books of Moses, which gave an account of the creation of the world, and also of Adam and Eve, who were our first parents;
12 And also a record of the Jews from the beginning, even down to the commencement of the reign of Zedekiah, king of Judah;
13 And also the prophecies of the holy prophets,
Jews divide their Tanakh (Old Testament equivalent) into three parts
: The Law (Torah), the Prophets (Neviim) and the Records/Writings (Ketuvim). Notice how this is exactly the way Nephi/Lehi divides it too.
