Pls Help – Uploading different files on sidebar from admin

I have so many products and every product have different pdf dowanloadable files, which appears on sidebar. Every time when i create new page/post for a product i have to write coding in (graceful sidebar plugin) Which is extra work for me. Is there any other and easy way to do it?

I have an idea for that but i am finding it difficult i-e On the admin page where we create / add new pages i want to put an option of uploading file. as soon as i upload that file and press update button. That file should appear on the sidebar of that page. can someone tell me how to do it.