Keyboard? What?! no. Unless its something out of harry potter I havent heard of any keyboard doing that. He has internet though a LAN....He could buy a wireless router to plug the lan into which would give him wireless. Easy fix. Its all up to his computer. If he is using the USB as an access card for his computer to get internet, then if his plan with his provider allows for sharing, then he might be able to. MIGHT!
He can use the Ipad without internet, however he would have to buy apps on the computer and transfer them to the Ipad. He cannot do anything else like surf the web, facetime, etc..
Best solution:
He needs a wifi connection. I would browse wireless routers. Its easy. You just plug the lan(internet cord) into that. He can then plug another cord from the router to his computer or if his computer allows for it, use it wirelessly.