Custom table

<?php
add_action( 'init', 'my_custom_table1' );
function my_custom_table1() {
    if ( ! class_exists( 'MB_Custom_Table_API' ) ) {
        return;
    }
    MB_Custom_Table_API::create( 'my_custom_table1', array(
    'address' => 'TEXT NOT NULL',
    'phone'   => 'TEXT NOT NULL',
    'email'   => 'VARCHAR(20) NOT NULL',
    'switch' => 'INT'
    ), array( 'email' ) );

}

add_filter( 'rwmb_meta_boxes', 'register_field_table' );
function register_field_table( $meta_boxes ) {
    $meta_boxes[] = array(
        'title'        => 'Custom table fields',
        'storage_type' => 'custom_table',    // Important
        'table'        => 'my_custom_table1', // Your custom table name
        'post_types'    => 'post',
        'fields'       => array(
            array(
                'id'   => 'address',
                'type' => 'text',
                'name' => 'Address',
            ),
            array(
                'id'   => 'phone',
                'type' => 'text',
                'name' => 'Phone',
            ),
            array(
                'id'   => 'email',
                'type' => 'email',
                'name' => 'Email',
            ),
            array(
                'id'   => 'switch',
                'type' => 'switch',
                'name' => 'Switch',
            ),
        ),
    );

    return $meta_boxes;
}