Unfortunately there’s no way at the moment to automate printing or export. Eventually Coda will add an action to run an export of a page or maybe a way to do combined export of multiple pages into a single PDF. But at the moment, you have to navigate to a page and manually do the export or print.
The best you can do is construct a separate page where you’ll have all the info from all the rows combined. There are limitations though: you can only have access to text (lists etc) from your Canvas column but not the views, charts you build there in your notes. But as long as those are simple text or checklists, you can combine those and preserve the content.
Here’s by and large a similar trick but let me know if you need help with your case specifically: