In our opinion Data Tables is one of the best tools in Excel, both for running sensitivities and for repeating calculations in operational models.
To see its benefit consider the example below.
We have a property that we want to purchase and we have put the salient details in a model and calculated the monthly repayment and the total interest paid over the period. But we want to see what these will be at different interest rates as shown in the red circle. We could change the interest rate and copy/ paste as values the answers but what happens when the details change, and this is time consuming anyway.