while (<DATA>){
    my @ju = split /\s+/, $_;

    push @{ $self->{code}{$ju[0]} },
        {
            event => $ju[1],
            month => $ju[2],
            am => $ju[3],
            pm => $ju[4],
        };
}

print Dumper $self->{code};

__END__

# trimmed down example output

$VAR1 = {
          'RF858' => [
                       {
                         'am' => '7.22',
                         'event' => 'U888',
                         'pm' => '4.20',
                         'month' => 'Dec'
                       }
                     ],
          'VS524' => [
                       {
                         'am' => '5.94',
                         'month' => 'Jan',
                         'pm' => '9.46',
                         'event' => 'U509'
                       },
                       {
                         'am' => '5.22',
                         'month' => 'Aug',
                         'pm' => '1.78',
                         'event' => 'U14'
                       }
                     ],
        };

##</code><code>##

for my $top_key (keys %{ $self->{code} }){
    print "$top_key\n";
    for my $href (@{ $self->{code}{$top_key} }){
        for (keys %$href){
            print "\t$_ => $href->{$_}\n";
        }
        print "\n";
    }
}