or just take it into an LDIF-like datastructure:

my $recordSet = 11;

open FILE, "< $file" 
  or die "Cannot open $file for reading: $!";
chomp ( my @list = <FILE> );
close FILE;

my @datasets = ();
while (my @subList = splice( @list, 0, $recordSet) ){
  my %hash = ();
  foreach (@subList){
    my ($key, $value) = split(/\s*\:\s*/, $_, 2);
      if (exists $hash{$key} ){
        push (@{ $hash{$key} }, $value);
      }
      else {
        $hash{$key} = $value;
      }
      push @datasets, \%hash;
      # if unique key exists, better use a Hash of Hashes
      # instead of array of hashes
    }
  }
}
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