Making an e-book Table of Contents is pretty easy.
Sometime ago, while I was looking at self-publishing, I came across Smashwords. For an author who is not based in the United States, there was a question of how to put my books on Amazon. I needed to have an address in the United States of America before I can get an account setup in Amazon. The next best thing was Smashwords.
I learned a lot from the guy there who started this online ebook store to compete with Amazon. He gave instructions how to setup a Table of Contents for e-books.
Note: I admit a video might make it easier but I know that there are plenty of tutorials in YouTube. So, this is just a 2-step version.
Step 1: Make a bookmark of each chapter
Using the Navigation screen, find the Chapter that you need. After that, at the Insert ribbon, select Bookmark and at the pop-up, type in Ch9 or C9 for Chapter 9.
Click Add and the new bookmark Ch9 is added.
Step 2: Make hyperlinks based on bookmarks
Tip: To make the link with chapter number and chapter title, select the whole line text and press Ctrl-C.