Example

$database =& JFactory::getDBO();

$result = $database->getTableList();
print_r( $result );

Result

Array
(
    [0] => jos_banner
    [1] => jos_bannerclient
    [2] => jos_bannerfinish
    [3] => jos_categories
    [4] => jos_components
    [5] => jos_contact_details
    [6] => jos_content
    [7] => jos_content_frontpage
    [8] => jos_content_rating
    [9] => jos_core_acl_aro
    [10] => jos_core_acl_aro_groups
    [11] => jos_core_acl_aro_sections
    [12] => jos_core_acl_groups_aro_map
    [13] => jos_core_log_items
    [14] => jos_core_log_searches
    [15] => jos_groups
    [16] => jos_mambots
    [17] => jos_menu
    [18] => jos_messages
    [19] => jos_messages_cfg
    [20] => jos_modules
    [21] => jos_modules_menu
    [22] => jos_newsfeeds
    [23] => jos_poll_data
    [24] => jos_poll_date
    [25] => jos_poll_menu
    [26] => jos_polls
    [27] => jos_sections
    [28] => jos_session
    [29] => jos_simplefaq
    [30] => jos_stats_agents
    [31] => jos_template_positions
    [32] => jos_templates_menu
    [33] => jos_users
    [34] => jos_usertypes
    [35] => jos_weblinks
)