what is the significance of tom's reference to the book he is reading?

The book The Rise of the Colored Empires espouses a racist philosophy which Tom seems to think is interesting, perhaps even a good idea. Perhaps Tom is more interested in the class system that he embodies - a rich man living in an elegant fashion that is very different from the way the average person lives.

I think that the content of the book implies a certain lack of intellect on Tom’s part. It also reveals Tom as a bigot. Tom is convinced in the superiority of the white Nordic race and all the garbage that goes with that. Tom pretty much lives in a vacuum of ignorance and entitlement.