I wouldn't call the division OT/NT minor or inconsequential by any means. It is an important one.
However, I think Patrick's answer was one of the best. The Bible is a unit, it is one story and Christ and the NT explanation of his final revelation. Read that way, the NT is the BIGGEST single portion of the Bible, when we consider it as a unit, all the matter of which is contained in a period of less than 100 years, one average human lifetime.
Moses' books cover phenomenal lengths of time. And still, the books of Moses and Joshua cover a single generation/lifetime of composition.
Then you have a gap, and then Judges, Ruth, Samuel--the Davidic era, along with many Psalms; Solomon and his writings could be grouped with this portion.
Then you have Kings (brief records of the prophets) and move into the writing prophets, a third grouping.
And lastly, the exilic and post-exilic era.
That's four major "periods" of biblical literature, before you get to the NT, and Christ, and an "overflow" of the Holy Spirit, culminating in the NT writings, a huge amount of explanation and clarification of all that came before.