Tips for Managing Large Documents in InDesign?

1. Don't embed images, link them.
2. Never copy images and paste them, use the place command.
3. Divide the book into chapters, separate indd files and combine them in an INDB InDesign book file.
4. Avoid EPS, use PDF/X.4 instead.
5. Work with styles (paragraph, character, objrct, table and cell styles)!

I specialize in production and consultation for long documentation in InDesign and FrameMaker (Adobe's other pagelayout program) and I would agree with the previous posts with just a few alterations...

Back up your files on a regular basis as mentioned by Zipping your project folder. Date it and move it to another hard drive and perferably cloud sotrage. 

Don't do a Save As as it can break the link with the book. Use the Zip method or do a Save A Copy instead.

You can link to Excel files into tables and update the link if necessary.

Don't forget about running headers/footers with variables. Here is a list of topics you may need to know:
https://www.ideastraining.com/classOutlines/InDesign_LongDocs.html

To repeat a couple of critical tips:

Use based-on parent pages as much as possible.

Use styles, styles, styles...

Never paste graphics--always place. 

Couple of tips:

You can open all files/chapters by selecting them in the Book file and double-clicking one.

You can save the open documents all at once by using Cntl-Alt-Shift-S (Win) or Cmd-Opt-Shift-S (Mac).

You can close the open documents all at once by using Cntl-Alt-Shift-W (Win) or Cmd-Opt-Shift-W (Mac).

I've written a couple of relevant articles in InDesign Magazine #123 and CreativePro Magazine #4 (subscription) that lay out many of the things you would need to know. Without knowing the specifics of your project it's hard to give concrete recommendations, but here are a few best practices for longer documents:

• Use the InDesign book feature if your catalog divides neatly into sections. This will make updates and catalog maintenance easier in the long term.
• Use a plug-in such as InData or InCatalog (emsoftware.com), especially if the catalog entries are complex or have images or illustrations.
• Style everything: paragraphs, character formats, objects, tables, tables cells. If you opt to make a Book, use the Book panel's synchronization options to keep styles, swatches, and parent pages synchronized.
• If you're using the Book feature, put all of your front matter, including the Table of Contents, into a separate document called something like "Front Matter.indd" so that you can rearrange, add to, or remove content sections independently. If you have back matter, like a company history page, or similar, make that its own document for the same reason.
• While working on the catalog, open all book documents at once. This makes for a quicker workflow in general and much better performance when updating or synchronizing swatches, styles, cross-references, etc.

You shouldn't have problems with crashes. Optimize performance by using SSDs and keeping all linked assets on SSD drives. Don't work across a slow network. Be sure you have at least 32GB RAM and a fast system drive for paging.

Yes, create your catalog from smaller parts - then use Book feature to link everything together. 

Do not embed anything - only link - so Place - not copy&paste. 

Do backup of your INDD files every day. 

Try to do Save As with a new name at least every other day. 

If you already have your 200 pages document in one piece - just save it as a smaller pieces and delete unnecessary pages from each piece. If you have one long Story - or you need to delete pages in the middle of the Story - it will require extra attention.