Transfer what sort of 'data' ? Do you have an app, or apps, on the iPad that supports what you want to transfer to it ? If you do, how you get the content into the app(s) will depend upon what the app supports e.g. file sharing (About File Sharing on iPhone, iPad, and iPod touch - Apple Support), via your wifi network, email, dropbox.
If you mean music or videos to the iPad's Music and Videos/TV apps : Sync your iPhone, iPad, or iPod touch with iTunes on your computer using USB - Apple Support