I agree, except I could not find the padding I expected to in the HTML or the CSS, in the ePub anyway. I didn't look at the kePub. I haven't noticed very many images yet. So I'm puzzled as to why a 700 page book takes up that much filespace, especially since the Amazon mobi is less than 1/3 as big as the kePub.

What strikes me as odd is that the Kobo ePub is 10MB and their kePub is 17MB, which is a 70% increase in size. I hope this is not indicative of all kePubs. The eInk readers tend to be processor challenged, so large files are going to be problematic.

EDIT: Okay I see why the file is so big. I looked at the ePub and it contains 64 images totaling 7.28 MB and it has the Charis SIL font embedded adding another 5.5 MB. We need to roll up a newspaper and smack the publisher in the nose!

[RANTING MODE]
Hey publishers and authors, what is so difficult to understand about using minimal formatting with eBooks? Geez, the whole idea behind eBooks is that we the reader should get to choose how we format your text. Let us decide which font, the margin size, font size, line spacing, et cetera! If we want to let you decide these viewing settings we would have bought the print version. So keep your bleeping hands off the style trigger. There is absolutely NO darn reason to use any styles period in an eBook (novels at least) other than character styles like bold and italics. Keep your darn TABLE, SPAN, STYLE, DIV tags and your darn CLASS attributes to yourself. That way your simplified HTML will look fine on any reader. If your book requires a lot of special formatting then chances are it is not a good candidate for viewing on 6" eInk screens.
[/RANTING MODE]