Unfortunately, Page Designer is very limited so you can’t do what you want to do with it.
I would recommend taking a look at Documint or On2Air Docs, which were specifically designed for Airtable.
Alternatively, you can use any document creation app you would like (Microsoft Word, Google Docs, Formstack Documents, etc.) with an automation tool like Make.
You can even send your Airtable data to an invoicing app like QuickBooks with Make.
There can be a bit of a learning curve with Make, which is why I created this basic navigation video for Make, along with providing the link to Make’s free training courses.
I am also available for hire as an expert Airtable consultant to assist with any of this.