Issues to address:
1. "separated by" does not appear in the current interaction. Possibly it refers to the "Styles" dropdown box.
2. "separated by" refers only to heading paragraph styles, but the Styles dropdown box seems to offer all PS that are in the document.
3. In general, it is hard to understand the descriptions on this page, in particular the consequences of selecting a Style.
4. Second sentence in first paragraph reads: "You can choose to create a separate page when a heading style that you specify is encountered in the document."
There does not seem to be any choice -- because the dialog requires the choice of a paragraph style. Is this sentence accurate?
5. Third sentence in first paragraph is hard to understand, especially " a separate page of links to all of the pages that are generated is also created."
6. Is it true, as the current page, asserts: "The titles of the HTML pages are created from the topmost chapter heading." ?
In my experiments, it seems that the title comes from the first PS that has the Para Style selected in the Save dialog.