Add below this code to bottom of the wp-content/plugins/favorite-plugin/init.php

init.php

if( !function_exists( 'fav_table_wrapper_class' ) ){
    function fav_table_wrapper_class($wrapper_class_arr, $table_ID){
        if( $table_ID == get_option( 'favorite_table_id' ) ){
            array_push($wrapper_class_arr, 'fav_table_list');
        }
        return $wrapper_class_arr;
    }
    add_filter('wpto_wrapper_tag_class_arr', 'fav_table_wrapper_class', 10, 2 );
}