Hello - I'm assuming that you are using Safari on your iPad for web browsing? If so, go into 'Settings' and then press on 'Safari' - a list of options will appear in the right-side panel - not sure whether you want to keep just some of the auto-fill entries or none at all, but take a look at this discussion on Private Browsing - might be a feature you would like?
Please post back if you have further questions, and if you are using another browser then again check its options in settings or visit their website - good luck!