The easiest way to find out what
FBReader can do is to try it on a Desktop computer. It will run under Windows or Linux, and there is a 3rd-party port to OS/X. Note that FBReader is highly customizable, so if it does not fit the you way you read e-books by default try playing with the options (crossed tools icon)
A good TOC is one reason to prefer .lit and .mobi e-books. If you have a multi-file html e-book with a .opf, it may have a formal TOC too. When a TOC is present, FBReader will allow it to be used for navigation (goto previous/next section actions, and via the TOC icon in its panel). FBReader does not try to build a TOC for you. Many html-based e-books have their own internal TOC near the start of the document, and at a minimum you can go to the start and then follow the internal TOC's hyberlinks. You can also tap on the position bar to move about in the e-book (if navigation is enabled).