my $script_name=$ENV{SCRIPT_NAME} || $0;

# ...

print qq(<form action="$script_name"><table>\n);
my $i=0;
while ( my ($idSensoren, $Beschreibung) = $select->fetchrow_array() )
{
  print << EOHTML;
  <tr>
    <td>$Beschreibung</td>
    <td><input type="text" size="10" name="beschreibung.$i"></td>
  </tr>
EOHTML
  $i++;
}
print "</table></form>\n";

#...