One of the first things I noticed is that saying those names out loud is sort of fun. They are like iron age tongue twisters. Why did we acquire some of those names and leave others? At first my theory was that the shorter ones are the ones we kept, but that didn't hold up very long. The second theory was that we kept names that fit into our language. That doesn't have any obvious flaws, except for the fact that each language changes names to suit anyway, think John, Juan, etc. It is obvious that we kept some because they were important, i.e. David, Matthew, Mark, Luke, John, Paul. These are the thoughts that come while reading the extensive lists of begats. I don't know that I learned anything of a spiritual nature, but it was fun to think about.
The thing I learned that I felt was valuable was the scope of history. In the LDS faith we have a tendency to talk about scriptures in quotable bits. This is probably unavoidable but it limits our mental scope a bit. The mosaic law is an example. It is easy while reading those chapters to get caught up in the minutiae of details and laws. The framework of the laws is much more interesting. The importance of remembering God is stressed over and over. The covenant between God and his chosen people and the blessings of obedience are repeated. The Lord didn't want to punish his people with all these laws, he wanted them to come closer to Him.
While the details of the history are interesting in a Jeopardy! way the scope of the history reminded me of the cycle we know so well in the Book of Mormon. We always talk about the cycle of repentance and prosperity and pride when we study the Book of Mormon. It is there in the Bible as well, though it was disguised a bit. It also reminded me of this scripture from the BoM 1 Ne 9:4
Upon the other plates should be engraven an account of the reign of the kings, and the wars and contentions of my people; wherefore these plates are for the more part of the ministry; and the other plates are for the more part of the reign of the kings and the wars and contentions of my people.Most of the Old Testament was written to record the "reign of the kings" We have some of the writings of the prophets, but all the histories were written with a very specific purpose: to make the Jews look good. I'm sure the essential facts are mostly correct but understanding the why helps with comprehension.
Since this reading took place in bits and pieces over the last year I couldn't say much specifically about this wonderful book of scripture, but those are the thoughts that popped up now.