Works for me

use strict;
use warnings;

my @allData = <DATA>;
my @tmpHeader = grep /^Test\s+\d+\s+of\s+\d+$/../^\d+\s+end$/, @allDat
+a;
print @tmpHeader;

__DATA__
Test 1 of 1
bala
bala
bala.
bala
138 end
blah
blah
[download]

Test 1 of 1
bala
bala
bala.
bala
138 end
[download]

Please pick more meaningful titles.