|Multiple character from a single key press usually indicates a dirty keyboard. As all the effected keys are in the same column it is certainly some muck getting in somewhere and shorting out some of the internal circuitry. Keyboard rate wont do anything about it.|
The first thing to do is to take hold of your keyboard, turn it upside down and give it a could shake. You will be surprised at how much crap comes out. That often solves the problem.
If the fails you can strip the key board down and clean it. If it is a membrane keyboard be careful of the little rubber caps under the keys. There is one for each key and they can jump out when you disassemble the keyboard. You can then disconnect the electrical components and give everything a good wash in warm soapy water ensuring it is thoroughly dry before reassembling and that means leaving it in a warm room overnight.
If it still fails to work on reassembley, then the only other option is a new keyboard. They are cheap enough.