Intech said:
How can I specify the number of rows in an Excel spreadsheet?
You can't "specify", basically. Each sheet houses a fixed 65536 rows, 256
cols.
But there are ways to make the sheet's appearance focused only on say, the
range A1

30, via either colouring "excess" rows to the right and cols below
with gray fill, for instance, or, by hiding away "excess" rows / cols. And
we could also "restrict scrolling" by freezing panes with say, Q31 selected
(Freeze via Window > Freeze Panes).