You might can download if you use a browser such as iCab Mobile. I believe they allow downloading within the browser and then you can use the "Open In..." function. I think...
If your ipad is jail broken, I know for sure you can install a download tweak from Cydia (the jail breaker's "app store"). Then, you can download practically anything.
But, as a normal occurrence, no, you can't download with the iPad (using Safari) as you can using a computer or laptop. Sorry.
Marilyn