I just bought this bundle, which is all O'reilly, so I'm assuming the ePub's are from them. Was looking at the Emacs one, and so far not too bad. But there are still issues, such as I came across a table that had the headers line at the bottom of one page, and the rest of the table on the next page. Things like this, you can probably put hits / rules in the ePub file for, but it still benefits more from having a human do the layout.

I already own that ePub so I'll check it on my end to see if it's specific to the Humble Bumble version. Which table should I check? Also, which reader are you using out of curiosity?

I tried it using Google play books, and also FBreader. The specific table depends on the screen size, font, orientation, etc. In my case, it was one of the tables in the preface, when viewing portrait mode on my phone. When bringing it up on my tablet, the same effect could be seen on any other table that happens to start at the end of the page.