You have to be a bit of a font nerd (or at the very least, spend a lot of time looking at fonts) to realize how its laid out. Same way you have to know/remember

You have to be a bit of a font nerd (or at the very least, spend a lot of time looking at fonts) to realize how its laid out. Same way you have to know/remember a decent bit of chemistry to know the groups the table is arranged in. Only, design is a bit subjective, so its not perfectly aligned like periods are in chemistry. So while a chemist can look at the table and realize that potassium might be substituted for sodium, a designer can look at this table and see that Avenir might be a good substitution for Din if needed. Some things that jumped out at me about its organization: Take a look at the serifs on the fonts. The further up/to the left, the lack of or smaller the serifs are. The further down and to the right, the greater the serifs are. The bottom row is script-esque/handwriting fonts. Also, they're roughly grouped by group classification; Sans serif Grotestque (Helvetica, Univers, etc), Neo-grotesque (Highway Gothic), Humanist (Gill Sans) and Geometric (Futura or Century Gothic) or Serif Old Style (Garamond, Palatino), Transitional (Times New Roman, Baskerville) or Modern (Didot, Century Schoolbook)