How can I get the rows to expand before a total?

[Guest]

I have a sheet for totaling a materials list, but the list has to be broken
down into separate subtotals. I'd like to be able to fill varying amount of
data between subtotals and grand totals without having to insert new rows
manually

 

[Tom Ogilvy]

When you put in your formulas, leave extra rows.

 

[Guest]

Well, yeah, but that wasn't really the point. Maybe Excel doesn't do it, but
I'd like a blank template where I could sort lists of varying length, and
where the last row before a subtotal automatically expands the way tables do
in Word when you press tab in the final cell