If you make a large sporadic income, it's either from holding multiple payroll jobs, in which case you can file a form that adjusts your yearly income to the CR

If you make a large sporadic income, it's either from holding multiple payroll jobs, in which case you can file a form that adjusts your yearly income to the CRA such that your withholdings will make sense, or you're a contractor/business owner and you're paying your own taxes, possibly in installments anyways. It's not like you're taxed at your peak monthly income. Withholdings are just estimates that can be adjusted.