#! perl
use strict;
use warnings;
use Data::Dumper;

my @list  = qw(abc def);
my $nelts = 3;

print "\nCase 1:\n";
my @array1 = (copy(\@list)) x $nelts;
$array1[0][0] = 'xyz';
$array1[0][1] = '123';
print Dumper(\@array1);

print "\nCase 2:\n";
my  @array2 = map { copy(\@list) } 1 .. $nelts;
$array2[0][0] = 'uvw';
$array2[0][1] = '456';
print Dumper(\@array2);

sub copy
{
    my ($list_ref) = @_;
    print "call copy($list_ref)\n";
    my @clone = @$list_ref;
    return \@clone;
}
[download]

output:

13:51 >perl 888_SoPW.pl

Case 1:
call copy(ARRAY(0x1c7dec8))
$VAR1 = [
          [
            'xyz',
            '123'
          ],
          $VAR1->[0],
          $VAR1->[0]
        ];

Case 2:
call copy(ARRAY(0x1c7dec8))
call copy(ARRAY(0x1c7dec8))
call copy(ARRAY(0x1c7dec8))
$VAR1 = [
          [
            'uvw',
            '456'
          ],
          [
            'abc',
            'def'
          ],
          [
            'abc',
            'def'
          ]
        ];

13:51 >
[download]