This is a few more characters, but I think it's a little clearer than your code:

printf "%10s\t=>%-10s\n", "keys", "values";
printf "%10s\t=>%-10s\n", $ky[$_], $vals[$_] for 0 .. $#ky;

__END__

      keys      =>values      
    barney      =>rubble      
     betty      =>rubble      
      dino      =>            
      fred      =>flintstone
[download]

Does the book really show that code?