In what way is this table layout not that accessible? I just fired up Voice Over and it read the page in the expected order. (Heading, left text, right text, chapter list.) The only complaint I would have is the bad alt text on images in the chapters (but every site has that problem it seems).

The font size can be increased without much issue (again, no more than most sites).

* I'm not blind or hard of sight, so I'm not an authority on these things. Just curious.

By all means, if you are the creator of a website, be as standards-compliant as possible. As a visitor, is it important if the browser is in quirks mode or not? Do you validate every website you visit?

Tables are fine for tabular data. The data on this site is (mostly!) tabular.