How to store PDF files: in sqlite or in the separate folder

I am developing Windows 8.1 Universal Application and I use Sqlite and Sqlite-Net to store the data. Now I need to add ability to store PDF files (1 Mb - 50 Mb) files in my application.

What is the best solution in this case? Store files in the Sqlite or store them into separate folder? Which folder will be better to use in this case?