Ok a Table of Contents is a way for you to list your articles or page's content
It is a great way to help your users navigate around your page easily, you then stand more chance of them staying on your site longer and returning as they will remember it was an enjoyable experience.
Ok first click on edit and organise your page:
Make sure each article or item has it's own heading, just highlight the heading > click on format > select heading/sub heading or minor heading - this will then be listed in the Table of Contents
(This page uses "announcements" page template. Each post creates a heading so add your T of C to the page to avoid creating all those headers and it means you can skip the first step above:)
Continue repeating the process for the rest of the items that you want to appear in the Table of Contents.
Now you are ready to add your Table of Contents:
Whilst in edit mode decide where you would like your T of C to appear and click using your cursor > the click on insert > Table of Contents
Customise the gadget .... and if you have sub heading under your main headings you can show them in the Table of Contents by customising the levels
Click ok and remember to hit save > sit back and marvel at your handy work, tweak where necessary .... let me know how you get on!