Configurable List Widget: Is it possible to duplicate a line?

Is it possible to duplicate a line?

Thanks!

I'm not  sure if I understood your question, but you can set up a min number of rows that will be displayed on the widget:

To duplicate a line you only need to click on the "Add" button, for example, click on the add member buttons on this sample form: http://form.myjotform.com/form/41112368425549 

Now, only empty rows can be added, but you cannot add rows with data entered on previous rows. 

If you're referring to something else, please provide us more details about it, we will be happy to help you.