It's a common heresy that there are dozens of other books that were unfairly excluded by men who put together the Bible. Nothing could be further from the truth. Many books are fraudulent in that they appeared hundreds of years after their supposed author died. So the book of Enoch and the Gospel of Thomas are examples of such books. Other books are historically accurate but were never considered scripture. First and second Maccabees are one example. The early church considered every book to be canon that's part of our New Testament today. In fact, quotes from almost the entire New Testament are part of the writings of the early church fathers following the deaths of the apostles.
Some books were never thought to be canonical. So Paul's letter to the Laodiceans has been lost forever.
(Colossians 4:16 NIV) After this letter has been read to you, see that it is also read in the church of the Laodiceans and that you in turn read the letter from Laodicea.
Here are other examples of books that have been lost because they weren't considered scripture:
(2 Chronicles 9:29 NIV) As for the other events of Solomon's reign, from beginning to end, are they not written in the records of Nathan the prophet, in the prophecy of Ahijah the Shilonite and in the visions of Iddo the seer concerning Jeroboam son of Nebat?
My favorite fraudulent book has to be the Gospel of Judas. The real Judas committed suicide after he betrayed Jesus so we're supposed to believe that he wrote down stuff about Jesus before he killed himself. No, it's obviously fake.