OSAP has set formulas where they decide how much you need based on your resources and assuming your parents give an amount based on their income. So long as you are in school, no, they don't demand an accounting of all of your expenditures.
I'd make sure to put it in a GIC that lets you cash out early for a reduced interest rate though (as opposed to one that you can't cash out or is more punitive) in case OSAP decides they paid you too much.
Now, if you drop out of school (or drop below the 60% courseload), that's a different story.