@Juan, I'm also interested in doing this for adding product manuals online. Please post back if you figure out a way to do this from a database field.

I have to insert product manuals too. If i can insert i will notify in this theme.

@Juan, I have added a repository to work on this module: https://github.com/OdooCommunityWidgets/website_product_attachments currently I have not yet started development, however I plan to use some of the features of : https://github.com/OdooCommunityWidgets/website_multi_image as this will work as a good starting point to pull multiple files (PDF's, pictures, etc.) onto the product page. Please comment back if you have any suggestions. If you'd like to collaborate on the module please feel free as I think this will improve the quality of the module and perhaps speed up the implementation of the first version of the module.