There are books of Enoch which mention “heavenly tablets”, but the books are treated as pseudepigrapha. That last term says that scholars even consider the attribution to Enoch to be false. Someone else wrote the books and put Enoch’s name on them in order to give them some stature.
The books of Enoch are considered Old Testament pseudopigrapha. There are plenty of New Testament psuedeprigraphic texts, usually with the names of some Apostle. The early church excluded such texts from the New Testament canon due to their suspect provenance.
Was there something written down from the time of the early patriarchs that contained the history of the human race from Adam? They had to have some writing in the days of the flood and after. I have been looking up steles and tablets, stone carvings were quite common in ancient times and are found in many places. Wouldn’t the ancient patriarchs have carved the history on stone tablets or steles? They had to have writing to preserve the very ancient history. Stone steles kept in some protected temple would have kept the early history for thousands of years.
There is no evidence that any of the Pentateuch was written down prior to the time of Moses. However, it could have been.
I would suggest that you might want to pay attention to Dr. Michael Heiser. He is a Hebrew and Old Testament scholar. One of his specialties is ancient religions which were extant at the time of Abraham and even before. I am sure that he would be quite familiar with any written material from these time periods.
Heiser is also an expert in ancient languages and contributes to secular studies of Egyptian hieroglyphics.
I include this article from his web site since it also mentions Enoch.
Heiser approaches ancient topics from a unique perspective, but he is quite orthodox in theology.