use strict;
use warnings;
my $data;
{
		local $/;
		$data=<DATA>;
}
$data =~ s/\n\s*\n(From: |To: |User-Agent: )/|/g;
$data =~ s/Arrival Time: ([^|]*\|[^|]*\|[^|\n]*)\n/$1|--\n/g;
print "Arrival Time|From|To|User-Agent\n\n";
print $data;

__DATA__
Arrival Time: May 2, 2013 10:37:50.813000000

From: <sip:639gwhuaping01-14@119.38.228.43>;tag=70c8b229-1c

To: <sip:639gwhuaping01-14@119.38.228.43>

Arrival Time: May 2, 2013 10:38:05.274000000

From: <sip:639gwhuaping01-01@119.38.228.43>;tag=70c8b229-2

To: <sip:639gwhuaping01-01@119.38.228.43>

Arrival Time: May 2, 2013 10:38:05.451000000

From: <sip:639gwhuaping01-11@119.38.228.43>;tag=70c8b229-16

To: <sip:639gwhuaping01-11@119.38.228.43>

User-Agent: Quintum/1.0.0 SN/0030E130409A SW/P108-09-10


##</code><code>##

use strict;
use warnings;

sub printdata {
		my $data = shift;
		$$data{"User-Agent"} //= "--";
		print join "|", @$data{ ( "Arrival Time", "From", "To", "User-Agent" ) };
		print "\n\n";
		%$data = ();
}

my %data;
my ($item, $value);
print "Arrival Time|From|To|User-Agent\n\n";
while(<DATA>){
		chomp;
		next unless ($item, $value) = /^(.*?): (.*)/;
		printdata \%data if $item eq "Arrival Time" and %data;
		$data{$item} = $value;
}
printdata \%data;

__DATA__
Arrival Time: May 2, 2013 10:37:50.813000000
...