Strategies for handling/editing a large "wiki" WP page

Site: https://www.atelieremmanuel.com

Suffusion theme
Relevant to this discussion I use, among others, Table of Contents Plus plugin.

I’ve created an online handbook which works quite fine. Employees can click in the table of contents to access the section they wish to read.

However, due to its size, it’s a bear to edit when I need to.

I’m wondering if there is a way that I could parse it out in multiple pages, whose contents, in whole, is then embedded into a master page.

For example, perhaps through a shortcode approach?

Thus the reader would have access to everything in one document, but when I wish to edit I would just find the appropriate page, rather than scroll through the entirety of the document.

Thoughts?