my @column_names = "col1" .. "col3";
my @values  = "val1" .. "val6";
my @td = [ @column_names ];
push @td, [ splice @values, 0, scalar @column_names ] while @values;

print "<table>\n";
for my $i (0 .. $#column_names) {
    print "<tr>", map("<td>$_->[$i]</td>", @td), "</tr>\n";
}
print "</table>\n";

##</code><code>##

my @th = "col1" .. "col3";
my @values  = "val1" .. "val6";
my @td;
push @td, [ splice @values, 0, scalar @th ] while @values;

print "<table>\n";
for my $i (0 .. $#th) {
    print 
        "<tr><th>$th[$i]</th>", 
        map("<td>$_->[$i]</td>", @td), 
        "</tr>\n";
}
print "</table>\n";