If your laptop runs Windows (which the vast majority of viruses, trojans and other malware targets), the iPad is infinitely safer, as none of those threats can affect the iPad.
You still have to take the same care about connecting to secured wireless networks as you would any other WiFI device, as once the data is in transit over the internet it's out of your hands.
Many banks and financial institutions, shops etc. provide their own iPad apps for managing your accounts. NatWest is one in the UK: http://www.natwest.com/personal/online-banking/g2/ipad-users.ashx
Banking websites, eBay, Amazon, etc. use a secure connection when transmitting sensitive information. This SSL (Secure Socket Layer) connection encrypts all data traffic to/from the site. When this type of connection is active you will see a "padlock" next to the site name and the URL will start with HTTPS.
You will be safe using these sites.