If you pay employees for working in Quebec, then that field is relevant.  In Quebec payroll deductions are separated between federal and provincial.

In Ontario, the column to the left controls the tax and both federal and provincial are deducted, reported and remitted to the CRA as one number.  You can change the label under Setup, Settings, Payroll, Names, Additional Payroll if you want but I don't think it will change anything regarding the calculations.