When you export a Schedule or Multi-Track page, the file has one People IDs: <list name> column for every list name used anywhere on the page. You can edit the file and import it again, which makes an export a good starting point for bulk changes.
Two things aren't in the file:
Lists with nobody in them. If you want an empty list back, add it again in the editor.
Lists of documents, which can't be imported or exported through a CSV at all.
Before you import the file again, it's worth reading what a re-import does to the lists you already have.
Related articles that might be helpful:
Start with the guide to lists on schedule items
See how you can import people into named lists from a CSV
See what happens when you update people lists with a re-import
Read more about exporting content from your app