Data driven test cases in one page

Hi, I have a small query regarding data parameterization. In training video 24 while explaining on xls sheet creation, you have asked to create all the cases in one sheet named "DATA".

Here my question:  If we add all the test cases in one page, isn't it difficult to add new test case ?? means We can add by inserting a row but how will we manage to read them as we already reading from certain rows and columns. the entire data placement of the sheet will change with multiple additions of test cases.