As others pointed out you haven't explained the context very clearly, however here's an example of how you can parse a logfile similar to what you show:

use strict;
use warnings;

use Data::Dumper;

sub readlogfile {
    my ($filename) = @_;
    open my $logfile, '<', $filename
            or die "open $filename: $!";
    my (@lookup, $entry, $trap);
    while (<$logfile>) {
        chomp;
        if ( /^Date:\s+(.+)$/ ) {
            push @lookup, ($entry = { DATE => $1 });
            undef $trap;
        } elsif ( !$entry ) {
            next;
        } elsif ( /^(SServer|Device|CString|Port):\s+(.+)$/ ) {
            $entry->{uc $1} = $2;
        } elsif ( /^\s+(Trap OID|Generic|Specific|Varbind|Type):\s+(.+
+)$/ ) {
            $trap->{uc $1} = $2;
        } elsif ( /^\s+Data:\s+(.+)$/ ) {
            push @{$entry->{TRAPS}{TRAP_LIST}}, $trap if $trap;
            $trap = { DATA => $1 };
        }
    }
    return @lookup;
}

print Dumper readlogfile("logfile.txt");
[download]

I've rudely assumed "Trap OID", "Generic", and "Specific" actually belong in a trap rather than the entry. If that's not the case you can easily edit it ofcourse.

In any case I hope this is useful for solving your problem