How to create instances of a html page and dynamically load into a list of the main page

I have main html page and then I need to add a dynamically created list of a template of another html file I created. Basically I have a template for one item of the list in a separate html page. So what I need to do is create instances of that html page, populate the correct data, and then add it to list of items on the main html page. I would know how to do this in java but I am not sure how to do this in html / javasript. I looked into forms but I am not sure if this is the correct choice? What is the preferred way to dynamically create html object instances.

Thanks