I know you must have your reasons for the way you store your data but I
believe it's common practice to store one record per row when using Excel as
a database so for your illustration you would have:

Cell A1 - Smith, Bob
Cell B1 - Toledo
Cell C1 - blank
Cell D1 - Dallas

When sorted, all elements would remain together.

Is the reason for a blank row to show the start and finish of each record?
If you store the data as above, you can shade alternate rows if desired

HTH