Ah, got it. "Row" as well as that we have "Add Column" is Page Builder. We did this differently in Trident (via Layouts), but would consider what can be done in 7.2. Thanks!
This request had been accepted for the development of d7.1.3 ( if I remember correctly ) . But I see that at the time was delayed ( d7.3 ). These links can help:
http://www.boonex.com/trac/dolphin/ticket/3104
http://www.boonex.com/forums/topic/Add-Row-for-Page-Builder.htm
http://www.boonex.com/trac/dolphin/ticket/3104
http://www.boonex.com/forums/topic/Add-Row-for-Page-Builder.htm