On your website, you probably installed a template so your content is always formatted the same way and respects some graphic rules. You can do the same thing for a Newsletter so once your own template is created, you will simply add some content in the main area of your template and you're done.
Search Area : this text input allows you to search a template.
Tags : with this input you can display the templates with a particular tag.
Sort by : this one allows you to sort your templates by name or creation date
On this listing, you can edit a template by clicking on it, delete it by clicking the red bin, and download it by clicking the blue icon.