Column to display number of pages for eBooks

[lxp]

For .pdf you can use ExifTool's PageCount tag, like here:

Columns: Extended EXIF (Picasa faces e.g.)

ExtendedExif - Script columns for extended and custom exif information. If you do not edit the script, it will add the following columns. ExifTool-Columns: Lens ID (the lens used on your camera, the script adds lens-ids for some panasonic lumix mo…

.epub and .azw don't have a standardized page size, so I am afraid you are out of luck.