The N800/N810 is a good choice. Note that it runs FBReader, which also reads Plucker and DRM-free MobiPocket e-books. So most of your existing files will work as is.
You can try out FBReader on any Desktop computer. There is also a two part screenshot tutorial made on a Nokia 770 (essentially identical to N800 for e-books):
Part I and
Part II. Click on any of the images to get a full sized version (which will be bigger on your screen than on the Nokia). FBReader is highly customizable, but this has the downside that you will probably have to customize it because the defaults are often not what you want.
From your list, FBReader does not handle tables and you can't edit e-books within FBReader. The Nokia's come with about 10 fonts. I have never added any new ones, but apparently all you need to do (as usual with Linux) is copy a .ttf font file to ~/.fonts.