According to Brant Gardner, what "this small account" (W of M 1:3) probably is NOT, is smaller in plate-size than Mormon's plates that he used for his abridgment. Nephi was commanded to forge both the large plates and small plates of Nephi (see 1 Nephi 9:1-5). While forging these original plates, it would have made much more sense to make them all the same size, and simply use some in one record and some in another. Thus we would not suppose that the individual sheets of the "small" plates would be any different in size than the rest of the plates. The term "small" probably relates to the quantity of sheets.
Modern descriptions of Mormon's complete set of plates have them held together with rings, implying no difference in size of the individual plates. Apparently, the physical size of the individual sheets that Nephi forged became the de facto size for metal plate records throughout Nephite history. [Brant Gardner, "Book of Mormon Commentary," [http://www.highfiber.com/~nahualli/LDStopics/WofM/WofM1.htm], pp. 8-9]