Paul Tabori takes a mostly humorous look at humanity's fads, fashions and follies. He considers a fad to be a "whim" for which exaggerated zeal is created. Fads are ephemeral and unpremeditated whereas fashions can be directed and planned, they are imposed and cyclic. He likens fads to comets and likens fashions to planets.
Duelling lasted many centuries so you have to take a very long historical view to see it as a fad. It is even more dubious to classify suicide as a fad. Revisionists are now claiming that the tulip mania wasn't as devastating as usually claimed.
The fashions he covers include underwear and cosmetics, the (male) fashion designers, the (female) queens of fashion, improvised poetry (which sounds more like a fad, though it has its modern counterpart in rapping), political revolutions, curses and swear-words, names.
In the section on follies, he covers spiritualism, astrology, communism (probably the longest chapter) and a chapter on the foolishness of not being anti-communist.
Some chapters are funnier than others and some chapters don't seem to fit with the section they are in. While there are occasional digs at communists in the early chapters, Tabori's politics are on full show at the end of the book.