vertical scrolling in a table

I have an empty table into which I want to enter data. I want to be able to view 10 rows but then also be able to scroll down to another 10 rows (and so on) to enter more data. You would not think this was so hard but I despite hours of searching and playing around I cannot find a way to do this.

If I have the visibleRowCount to 10 and rowCount to -1 (which I assumed would mean let me have as many as I want?), then the scrollbar is greyed out.If I set the rowCount to say 50 then my vertical scrollbar is not longer greyed out and I can scroll down. Howver, I then get a short dump in CL_WDR_TABLE_DATA_PROVIDER->GET_VISIBLE_TABLE_DATA concerning an ASSERT.

Can anyone please point me in the right direction with this?

Thank you.