Word is not a layout tool, though it often gets used that way, especially in a business environment. In those cases, rather than typing a table of contents (TOC) out by hand, Word comes to the rescue. Find out the many ways to manipulate a Word-generated TOC in my Oct–Nov Technically Speaking column in the Copyediting newsletter. (subscription required)
To learn even more about MS Word, buy my self-study enhanced ebook: Editing in Word 2016.