The overall book is very well put together. Basically goes over 450 home consoles, (rounded to 420 full console reviews - since the more obscure 30 are semi explained in the back with no photos) with full photos, descriptions, last game published until, complete models, and how well they sold amongst the competition at the time.
The book is split up into 4 segments. First explains the different storage of each console (floppy disk, Hudson's Hu Card, GDROM ect) briefly. Second goes over first computer/arcade built. Then branches off into 4 eras.
Beginning (Atari, C64, MSX ect) until the crash,
return of 8-bit (Nintendo, PCE, SMS ect),
32/64-bit + handheld - (Saturn, Nuon, 3DO ect)
until Today: which is Xbox and Nintendo DS since it was published in 2003.
Page example:

In the 16-bit era, Sega Mega Drive going on 4 pages long (usually 2)

Introduction page heading into the 16-bit era consoles