This dialog is for conveniently creating new forms based on you own templates.

By default dialog have one tab "Standard", on this tab is showing templates placed into main "Templates" folder. This tab can't be removed.

But if you need more flexibility and categories for your templates, just create new subfolder under "Templates" folder And place into it you templates. Now, when you open gallery dialog, you will see new tab with the same name as created subfolder and with your templates inside. You can create unlimited number of folders.

When you create form you want to make template, you can assign icon in form and description in the "Description" property. This information will visible in gallery. If no icon assigned to your template, default one wilk be used.