It's important to distinguish the Five Books of Moses -- aka "the Pentateuch" aka "the Torah" from "the Jewish Bible" or "the Old Testament" from "the [Christian] Bible". The [Jewish] Bible as a whole is openly and unambiguously the work of multiple authors over multiple eras.

The first five books are a separate coherent unit; the inter-book divisions do not correspond to authorship in any theory I've ever heard of. This article was about teasing out authorship in those first five books.