Specify these below mentioned things in the Create New Template from this database dialog box.
Name: give any name to your template file. The template file is get saved with an extension .accdt.
enter a text as a description. That appears in the tooltip.
Select the user template to have it appear under Application Parts.
Icon: Select an icon to display for the template or application part. Click Browse to select it.
Preview: Select a bigger size image to display for the template in the start and new screen or backstage view. You can browse for more images.
Select a table to use as the primary table for the application part this table relates the application part to other tables in the database.
Make selection for the form that open by default when the template database gets open.
Select to save the database as an application part, clear to save the database as database template.
Include Data in Template:
By default the database will get saved without data but if you want to include the data then select Include All Data in Package.