Refer to last cell in column or in row in a function

Hi. Is there a way to refer to the final cell in a column and/or row? I am making a spreadsheet that will have some values in columns and then a total in the final column. This spreadsheet will be manually updated occasionally to add a new row with new values, and therefore a new total. This new info will not replace the preexisting info, hence the new row. I want another sheet to always refer to the total cell that has the most up-to-date total, which will be the final column in the final row. The final column number will probably be consistent, but you see the final row will always be changing. Is there a way to do this?

To put it in other words, for example:

Col 1 | Col 2 | Total

59 | 1 | 60

In this case the function would refer to A3. But later this sheet may be updated with another row

Col 1 | Col 2 | Total

59 | 1 | 60

60 | 5 | 65

Now I want the function to refer to B3. But I don't want to manually update the function each time. So I want it to always refer to the final cell in column 3. Is this possible?

Thank you for any help.