If the Graphic Tablet uses a seriel Interface you would need a seriel->USB adaptor. I use them on a Temp/RH unit to download the data and On an O'scope to download waveforms to the laptop.
You would also probably need the driver software for the operating system.
For Info, only reference to I%, their are several types; P/h-55/57, P/H-67, Z68, and X58, In your case it does not matter. You may have a serielo port on your MB and just need to take it to a header.