#! /usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my $array = [
    { page => 1, },
    { page => 2, },
    { page => 3, },
    { page => 4, },
    { page => 5, },
    { page => 1, },
    { page => 2, },
    { page => 3, },
    { page => 4, },
    { page => 5, },
];

# behalte alle mit page == 5
@$array = grep { $_->{page} == 5 } @$array;

# oder behalte alle mit page != 5
#@$array = grep { $_->{page} != 5 } @$array;

print "Kontrolle:\n";
print Dumper $array;