Since Views PDF uses its own display type with its own formats other formats that are usually available in block or page views cannot be used. This includes grid views or formats provided by other modules like the Views Matrix Module.
To get such views into a PDF generated by Views PDF you need to first create a pdf of the page you like to include. The print module is a good candidate for that. Configure it until you can access the content you desire as a pdf. The dompdf library is tested but others should work as well.
Next enable Append View module which is shipped with Views PDF and add a new "View: Append View" field to the views_pdf view. In the fields configuration you can provide the url of the pdf generated by the print module.
- This is only meant for (html) content that cannot be included with Views PDF itself. Views PDF is generally faster but the used library seems unable to render complicated html.
- Tested to work with the dev version of views pdf.