Passing multiple array to drupal_json_output() is not giving correct output in jquery ajax
To setup a service which returns a json formatted data, you should set the delivery callback to drupal_json_output. This will only output the service data and not all the HTML defined in your theme.

For example

function YOURMODULE_menu()
{
    $items = array();

    $items['service/ajax'] = array(
        'title' =&gt; t('Ajax service'),
        'page callback' =&gt; 'YOURMODULE_ajax',
        'delivery callback' =&gt; 'drupal_json_output',
        'access arguments' =&gt; array('access content'),
        'type' =&gt; MENU_CALLBACK,
    );

    return $items;
}

function YOURMODULE_ajax()
{
    for($i = 0; $i &lt; 10; $i++) {
        $arr = array('message' =&gt; 'test'.$i, 'data' =&gt; 'data'.$i);
        $arrs[] = $arr;
    }

    return $arrs;
}