what is the significance of the dimensions?
With age .... comes width.
Tops of tables and sides & doors of blanket chests and cabinets made prior to say the 1880's were often made from one (1) board that was sawed from "virgin" timber (BIG trees).
Most all the "virgin" timber east of the Mississippi had been cut by 1900 except in a few places that were inaccessible to loggers at that time. Actually inaccessible to the horses that were needed to drag the log out after it was cut.
I remember seeing a photo that my mother had, of my grandfather and his logging crew, that was taken in Webster County, WV, just after they had "notched" a tree they were cutting with their cross-cut saw. All five (5) of them were sitting in the "notch".
For those unfamiliar with what a "notch" is, it is a "piece-of-pie" shaped wedge that is cut out of the side at the base of the tree to control the direction the tree falls and to insure it "jumps" off the stump, otherwise it will likely "split" right up the length of the log.