Use rich text Headings as indicators for sections and sub-sections in your guide. This not only provides heirarchical organization and formatting but also makes it easy for screen readers to scan and jump to different content areas.
Here is an example default 2x2 table with a header created within the rich text editor.
|Header A||Header B|
|cell A1||cell B1|
|cell A2||cell B2|
Take caution when copying & pasting content from any source. Many times hidden style code will also be copied along that could break with best practices and introduce inaccessible content.
There are a few ways to avoid hidden style code from being placed into your guide. The rich text editor has a few useful tools to use.