my %tab = ( abc => [4, 20], def => [9, 20000], ghi => [16, 200000]  );

##</code><code>##

#! /usr/bin/perl -w

use strict;
use CGI;
my $q = new CGI;
my %tab = ( abc => [4, 20], def => [9, 20000], ghi => [16, 200000]  );

print $q->table( {-border=>"1"},
    $q->TR([
        map {
            $q->td( $_ ) . $q->td( $tab{$_}->[0] )
        } sort keys %tab
    ])
);

##</code><code>##

<td rowspan="2">abc</td><td>4</td>
<td>20</td>
<td rowspan="2">def</td><td>9</td>
<td>20000</td>
<td rowspan="2">ghi</td><td>16</td>
<td>200000</td>

##</code><code>##

my $flipflop = 0;
print $q->table( {-border=>"1"},
    $q->TR([
        map {
            ++$flipflop % 2
                ? $q->td( {-rowspan=>"2"}, $_ ) . $q->td( $tab{$_}->[0] )
                : $q->td( $tab{$_}->[1] )
        } map { $_, $_ } sort keys %tab
    ])
);