Prefill rows from one expanding table to another expanding table

I have a form that has two sections in which each has an expandable table.  Each table starts with 3 of the repeating rows appearing.  When information is entered in the Maintenance Operation field in the table in the first section (Estimate of Maintenance Costs) it prefills to the corresponding field in the table in the 2nd section (Maintenance Expenditure Statement).  However, if more than 3 rows are entered only the 3 original rows appear in the table in the second section.  It will not allow additional rows.