Ipad has its own brain, I touch for a website and it brings up ads and other websites which I have never had before. It just searches and brings up anything.
Sometimes websites will redirect you without you controlling the iPad at all. It happens sometimes, especially if you visit some less-than-squeaky-clean websites. I'd say avoid any of those sketchy websites and, if the problem persists, you may have to clear your history and website data by going to Settings>Safari>Clear History and Website Data.