"You want to eat pasta."
Translation:Rwyt ti eisiau bwyta pasta.
This is explained in the 'Hints and Tips' notes for the earlier section on 'wanting', 'Wanting1'.
It is just a written representation of one of the several common pronunciations of eisiau that are used. In this case it comes from north-west Wales. Unless you are actually amongst people who write isio, stick with writing eisiau.