Jellby, the book is full of widows and orphans. It's probably literally impossible to avoid them and still have the book looking good, without generously large margins.
The considerable margins of paper books give a good bit of leeway for trickery that can help avoid them. While I've gotten rid of some outrageously ugly widows/orphans by forcing pagebreaks, I will not even try to get rid of less egregious ones.
Even the LaTeX typesetting of this PDF is definitely subpar, by professional publishing standards, as I do not have the energy to attend to it as thoroughly as it requires... however, even like that, it still looks better than any eBook of Casanova's Memoires that I have ever seen.