Row Count Based On Cell Value

I have a table that is say 5 colums wide. The top row in the table are just labels (Number, Height, Width, Density, Mass for example)

The rows under that row would be filled with manually inputed data (except for "Number", this would automatically fill down)

The last row of this table, however long it may be (however many datapoints) has data that sums and averages the data above it (average height, width, density, etc)

So if I have say 10 samples, I need a total of 12 rows, 1 for the header and 1 for the footer and ten for the samples.

What I would like, is to have a cell that I input the number of samples into (say there are 53 samples, Cell A1 would say "53) and the table with the data would automatically adjust (insert or delete rows, with the cumulitive data adjusting appropriately)