Word allows pulling part of a logical paragraph into the TOC using a Style Separator.

See:
How to create numbered headings or outline numbering in Ribbon Versions of Word by Shauna Kelly
Generating a Table of Contents - Complex Documents
How to create a table of contents in Microsoft Word by Shauna Kelly

Otherwise, you can mark text separately for a Table of Contents using TC fields just as you would for a Table of Authorities. The complex documents link above goes into both of these methods.