Download excel file

You'll need an app on the iPad, Documents to Go is mentioned frequently for this purpose

Not sure if you have Numbers installed on the iPad? Numbers (Apple's Excel), Pages (Apple's Word) and Keynote (Apple's Powerpoint) are all available through the App store if you find yourself using those types of docs.

If I were you, I wouldn't go near Numbers if it's Excel compatibility you are looking for. Docs to Go and Office2HD are much better at that, IMO.

Numbers is a nice app, but very poor at Excel comatibility.