If Moroni has not written "the hundredth part" (Ether 15:33) of the record of Ether, and if Ether did hide "them" (referring to the record); Is it reasonable to suppose that about 33 of our pages (the length of the Book of Ether) would turn into 3300 pages if the full "24 plates" were translated? Does the phrase "the hundredth part" have some other meaning?
According to Verneil Simmons, Ether does not tell us (or perhaps the fault is Moroni's who made the abridgment) that the Jaredite people kept civil records but it is evident from his history on the plates that they had to have done so. Ether might have memorized the correct genealogy of his own line of descent, which he records as the proper king-line, but he could not have supplied the details of the various reigns, the plots and counterplots, names and places, details of the famine and its results, their cultural achievements, etc., without reference to written records. [Verneil W. Simmons, Peoples, Places and Prophecies, p. 238]