The value for the browser control is a url .. to an html page (whether on a web server or internal file file:/// ) .. if your html page can have 2 PDF files, then yes, you can have the browser open 2 or multiple PDFs.

The HTML could use an embed tag, such as 

<embed src="http://example.com/first.pdf" width="500" height="375" 
 type='application/pdf'>

some text

<embed src="http://example.com/second.pdf" width="500" height="375" 
 type='application/pdf'>

Thanks shjerpe, that opens possibilities.