This book is very interesting. It's supposedly written about 300BC, whereas Revelation is around 70CE.
In the bible, the book of Daniel, it speaks of "the watchers". The watchers are spoken of in Enoch and somewhat explained.
I forgot where but in the instance in the OT of the 2 goats, one for YHWH and one for Azazel, in the book of Enoch Azazel was one of the rebellious angels.
In the bible and I think Revelation where it speaks of angels bound in darkness awaiting judgement, the book of Enoch has many details on that, as well as their being cast into the lake of fire. (in teh bible Revelation is the first place I saw that but if it was in book of enoch, that's almost 400 years ahead).
If the book is definitely confirmed as being written prior to the book of Revelation, I wonder why there is so much silence on it other than among mainstream christian religions.