The oldest documents held by RBML are over 500 cuneiform tablets, ranging in date from 2300 B.C.E. to 300 B.C.E., from the Sumerian, Old-Babylonian, Kassite, and Neo-Babylonian Periods. There are also a few cylinder seals.
Some 455 of the tablets were purchased for Columbia College in 1895. Sixteen tablets were given by Professor David Eugene Smith and 34 by George Arthur Plimpton as part of their libraries. Plimpton's gift included Plimpton 322, possibly the most famous mathematical tablet in the world. There have been a few gifts of tablets since.