use Data::Dumper;

my @array = qw(foo bar baz);
my %hash;

for (1..5) {
   my @array = qw(foo bar baz);
   $hash{$_} = \@array;
   undef @array;
}
print Dumper \%hash;

for (1..5) {
   my @array = qw(foo bar baz);
   $hash{$_} = [@array];
   undef @array;
}
print Dumper \%hash;