Fixed head rows

I would like to know how to add some rows as fixed head above my work table entries. I managed to split the table (by dragging the thick line from the right upper corner), but now the table displays “two tables” - I see twice row 1.

What I would like is to have row 1-4 in the head box and the other rows (5-N) below the thick black line.

Thanks for your help

Window → Freeze