If the books in the Bible were written by apostles, was Moses considered an apostle? What of Isaiah and Samuel? Were they considered apostles? Is it not said in the book of Matthew that nothing was to be taken from the Old Testament? I'm just curious because if this is true, those books in the Old Testament have been not only taken away but also ignored. The book of Enoch, which was the first prophet and has historical value was removed. The book of Jasher which is mentioned in Second Samuel had been removed and is also referred to in the book of Samuel twice if I'm not mistaken. I could be wrong. Can you explain?
The books in the New Testament were written by apostles and by prophets closely associated with the apostles. Apostles did not exist prior to Jesus because the apostles were eyewitnesses of Jesus (I John 1:1-4). The writers in the Old Testament were prophets.
The mistake you are making is that if a book appears claiming to have been written by an ancient prophet, then you think it must appear in the Bible. The reason the Book of Enoch (of which there are several versions) is not in the Bible is that it is known to be a fraud. See: Why don't you use the Book of Enoch? for details.
The second mistake you make is to assume that all books mentioned in the Bible are inspired writings. The only thing stated about the book of Jasher is that it contained copies of a few things which also appear in the inspired Scriptures. See What is the Book of Jasher? for details. And yes, you are mistaken about the references to the Book of Jasher.