[KevinH]

No. What I am explaining is that one big html file is not the right way to do it since some older e-readers barf when trying to open an xhtml file longer than about 200k.

So first thing before creating a table of contents, you should split the one big file into separate sections/chapter files using Sigil. This ensures each chapter will start on its own page in the book.

Then use the Sigil tools to create the html table of contents.

Again, I strongly recommend reading the Sigil Users Guide, especially the tutorials for beginners.

It explains all of this.