Please have a look at the documentation:
- Create a Microflow that creates a New Entity that specializes from System.FileDocument
- Create a Document Template that contains the content you have already available
- Make sure the content is passed to the Microflow from your grid(s).
- Add the Generate Document Action to the Microflow
- Setup the input parameters in the Generate Document Action (don't forget to add the template as well).
- Add the Download file action as action to your Microflow and pass the New Entity as Input.
You can add an export excel button to your datagrid but unfortunately listviews do not support this functionality. You can check out the excel exporter module and create a template that you can export to excel from a microflow.
Here is a link to the module:
Here is a how to guide for this module:
and some documentation on the export to excel button:
Hope this helps!
Edit: I just realized you said PDF not excel. Sorry about that! Please refer to Aswin's answer. I will leave this answer here in case you want to know about excels.