Before you go out looking at houses, you need to have a price range in mind. That price range is based on how much the monthly payment is going to be. The principal is a portion of the actual loan that is being paid back. The interest is what you are paying on the balance of the loan each month to the lender for borrowing the money.
Taxes refer to property taxes and insurance is self explanatory.
In order to figure out how much house we can buy, we need to know what the monthly payment is going to be. To figure out the monthly payment, we must do a what-if analysis. Further, we must do a what-if on the interest rate. If your table is correct, the final balance should zero out at month 360. You will notice that the additional payment column so far is zero.