Can we upload a word template and edit it via JotForm then save it as our own template again?

I'd like to auto populate other fields in my document rather than doing each page manually or via 'copy-and-paste'. 

My understanding is that you want to pre-populate the form fields with data. You can actually pre-populate the fields with data through the URL. Here's a guide: Prepopulating-Fields-to-Your-JotForm-via-URL-Parameters

You may also use the Field Prepopulator App, here's the link: http://prepopulate.jotform.io/.

Hope that helps. Thank you.