You can use the Page Designer Block to create your own customized documents that will pull information from your Airtable records. You would then need to manually print your document as a PDF file, and then you could manually email the PDF to the customer, as well as manually attaching the final PDF into an attachment field (if you’d like to keep a copy of the PDF on file).
For significantly more automation, Airtable also has the Formstack Documents Block built into it. This costs money because you’ll need to pay for a Formstack.com account, but it will create a PDF/Word file for you, and then automatically embed the document back into your Attachment field for you. Even better, Formstack can be setup to automatically email the PDF file for you as well.
You can do a similar thing (without the automatic emailing part) with DocuPilot.com and this extension: it will generate the PDF/Word document for you and then embed the document into your Attachment field.
For other types of automations, you would need to turn to some external tools to do that, such as Zapier or Integromat. Although I’m not 100% sure if Zapier and Integromat can grab attachments out of Airtable and embed them in an outgoing email. They might be able to do that — someone else would likely know that better than me.