It seems that you would like to know how to open multiple PDF files with the reader app on windows 8.
I will certainly help you with this.
Please be informed that currently the Windows 8 Store app “Reader” will not have an ability to open multiple PDF files, or have multiple instances open
at the same time. This is a design feature that is dependent on the Reader and the operating system. A feature change for the Reader is being investigated in a subsequent release of the product. The exact dates for the feature change have not been determined.
For more information, visit the following link and check.
When clicking on a link to a PDF file within a PDF file in Windows 8 Reader nothing happens