my @data = map {chomp; [split /:/]} <DATA>;

my $width = length $data[0][0];   # Assume they're all the same length.
my $Width = @{$data[0]};

my $divider = "-" x (($width + 1) * $Width);

my $topline = $divider x 2; chop $topline;
say $topline;
foreach my $line (@data) {
    print "$_|" for @$line;
    say "\n$divider";
}

__DATA__
A:B
C:D

##</code><code>##

-------
A|B|
----
C|D|
----