Follow these instructions to clear the web / browser history on your iPad.
Open the Settings app on your Home page and tap Safari. Scroll down and tap "Clear History." You can also clear all cookies and data and set Safari to Private Browsing mode from this screen.
Open your Chrome app and tap the three bars in the top right hand corner. Select Settings from the drop box and click Privacy. From here you can:
Clear Browsing History
Clear Cookies, Site Data
You can also clear your Saved Passwords, Bookmarks and Autofill Form Data from this screen.