...
use Data::Dumper;
print Dumper(\%data);

foreach my $surname (keys %data) {
   my $family = $data{$surname};
   foreach my $given (@$family) {
      print("$given $surname\n");
   }
}

##</code><code>##

$VAR1 = {
          'flinstones' => [
                            [
                              'fred',
                              'barney',
                              'willma',
                              'betty'
                            ]
                          ]
        };
ARRAY(0x2254d8) flinstones