Remove Tables & Figures from Table of Contents
Solution 1:
Stop using your Heading Styles for your Captions
Even without a sample your response about them showing up in the Navigation Pane is enough for a diagnosis.
Use the Caption feature to caption your Tables and Figures (or equations or pictures). It is on the References Tab in the recent Windows and Mac versions of Word. Usually, you will want to create the Caption by selecting the figure or table and then click to add a Caption. This is my writing on adding a caption.
Anything that you type or add in one of the first three built-in Heading Styles will show up in the Navigation Pane and, by default, in a Table of Contents.
See Word MVP Suzanne Barnhill' page on TOC Tips and Tricks for more on the TOC. For times when these styles do not show up in the Navigation Pane or TOC see my Article on the Microsoft site about that.