Until recently I have used the strategy that you have shown above. I would now suggest using Data::URIEncode.

You would begin by using a form that looks similar to the following:

<form ...>

<table>
<tr>
  <td><b>Username 1</b></td>
  <td><input type=text name="users:0.username"></td>
</tr>
<tr>
  <td><b>Email</b></td>
  <td><input type=text name="users:0.email"></td>
</tr>
<tr>
  <td><b>Name</b></td>
  <td><input type=text name="users:0.name"></td>
</tr>
</table>

<table>
<tr>
  <td><b>Username 1</b></td>
  <td><input type=text name="users:1.username"></td>
</tr>
<tr>
  <td><b>Email</b></td>
  <td><input type=text name="users:1.email"></td>
</tr>
<tr>
  <td><b>Name</b></td>
  <td><input type=text name="users:1.name"></td>
</tr>
</table>

</form>
[download]

So far so easy. You can use pretty much whatever templating tools you want for generating the html - clear from hard coded html (don't do that), to CGI html methods, to Template::Toolkit (I'd suggest doing that).

When the form is posted to cgi script, just pass the CGI query through Data::URIEncode.

use CGI;
use Data::URIEncode qw(query_to_complex);
use Data::Dumper qw(Dumper);

my $q = CGI->new;
my $data = query_to_complex($q);

print "Content-type: text/plain\n\n";
print Dumper $data;

__END__
Will have printed something similar to:

$VAR1 = {
    users => [{
        username => "...",
        email    => "...",
        name     => "...",
    },{
        username => "...",
        email    => "...",
        name     => "...",
    }],
};
[download]

You'll still need to do all of the validation, but getting the records into the right structure is already done.