Which book in the bible has unknown Arthur?

Answer 1

There are a few. This is a current list of books thought to have unknown authors:

Joshua (thought to have been written partially by Joshua and edited by Samuel)

Judges (traditionally attributed to Samuel. Unknown.)

Ruth

1, 2 Samuel

1, 2 Kings (traditional author is Jeremiah. unknown)

Esther

Job

Lamentations

Hebrews (traditional author is Paul

Revelation is debatable between the traditional John the Apostle, son of Zebedee and John the Presbyter.

Note: The authorship of some of these books are attributed to a certain writer, however, it may be believed that someone else is responsible for the penning of the text or compiling it. Tradition gives authorship to many of the books but most are not proven and little evidence exists for conclusiveness.