Website Product Attachments stores multiple product attachments/files in a tab: 'Product Attachments' under Sales >> Product. This module is designed to store product manuals and any other files that you would like your users to be able to download from the product page.
Website Product Attachments
sudo git clone -b 8.0 https://github.com/OdooCommunityWidgets/website_product_attachments.git This will provide you with the latest working 'stable' version of the module built for the 8.0 branch. Please be advised this module is still under development.Choose one2many, many2many or a mixture of a few different fields and field types (eg. one product manual covers many products)