Documint, On2Air, and other 3rd party apps let you automatically generate a PDF to attach to a record’s attachment field, and from there you can email the PDF to someone using an Airtable Automation.
Page Designer pages can only be accessed by the user directly opening up the app. You’d have to manually download/attach the PDF of a page to the relevant record.
On2Air’s might be the easier one since it uses Google Docs and most are familiar with that. DocuMint has their own proprietary document builder that works well, too. ITs a bit more visual an editor. I guess if you need mostly text/tables then On2Air, if you need to neatly arrange graphics DocuMint might be better
Both handle multi-page documents just fine.