Jarom notes that he does not write more because of the constraints of space. Certainly that is beginning to be the case, and the very short entries of the next several writers will confirm that. However, the last writer does find some room, and we must suppose that the room existed also for Jarom. He writes little because the wars (apparently one of the most salient aspects of Nephite society during his lifetime) are available on the other "kingly" records.
Sociological: There is a very brief but important note at the end of this verse. Jarom notes that the other plates are "according to the writings of the kings, or those which they caused to be written." This is important because it is a significant shift from the time of Nephi, who kept the records himself as the king. It is likely that his next successor (or two) also kept them personally, but by the time of Jarom the political and social complexity is sufficient that the kings cause them to be written. This is a subtle but unmistakable indication of the increasing complexity and stratification of society (which, as we remember, was a theme against which Jacob had preached).