1) Get the old content
2) Concatenate old + new
3) Replace old with old + new

for (var i=0, l=arr.length, a=[]; i<l; i++)
{
    a.push('<tr><td name="pieTD">' + arr[i] + '</td></tr>');
}
var table = $('table');
table.html(table.html() + a.join(''));

The get, concatenate and replace are all in the last line. For me, this is almost 4 times as fast as the method given in this article. It is also very readable.

      var arr = reallyLongArray,
                textToInsert =  ['<tbody>'],
                length = arr.length,
                $table = $(table),
               chuck = 10
      for (var a = 0; a<length; a += 1) {
          textToInsert.push('<tr><td name="pieTD">');
          textToInsert.push(arr[a]);
          textToInsert.push('</td></tr>') ;
         if( a % chuck == 0 ){
           $table.append(textToInsert.join(''));
        }
      }
     textToInsert.push('</tbody>');
    $table.append(textToInsert.join(''));

      var arr = reallyLongArray,
                textToInsert =  [''],
                length = arr.length,
                $table = $(table),
               chuck = 10
      for (var a = 0; a <length; a += 1) {
          textToInsert.push('');
          textToInsert.push(arr[a]);
          textToInsert.push(' ') ;
         if( a % chuck == 0 ){
           $table.append(textToInsert.join(''));
        }
      }
     textToInsert.push('');
    $table.append(textToInsert.join(''));