I want to show a new table on checkout page to show how much user save on a product ACF WordPress WooCommerce

Solution:

WordPress in general and WooCommerce have the thing called “Hook” to help us add our custom data.

This article is an introduction and example about WooCommerce Hooks

This is a virtual version of hooks on the WooCommerce checkout page.

So as your needs, you may use woocommerce_review_order_before_cart_contents hook, add this code to functions.php file in your theme:

Add to the checkout page in general

add_action( 'woocommerce_review_order_before_cart_contents', 'add_member_info' );
function add_member_info() {
   echo '<div class=”member-message”>Become a member will save $100</div>';
}

Get data from a custom field in the product

I. To show in the single product

function cw_change_product_price_display( $price, $product ) {
    $my_field = get_field('member_save', $product->ID);
    $price .= " | Member save $$my_field";
    return $price;
}
add_filter( 'woocommerce_get_price_html', 'cw_change_product_price_display', 10, 2);
add_filter( 'woocommerce_cart_item_price', 'cw_change_product_price_display', 10, 2);

II. To show in the checkout page

  1. Add custom data with the product to Card
add_filter( 'woocommerce_add_cart_item_data', function ( $cartItemData, $productId, $variationId ) {
    $member_saved = get_field('member_save', $productId);
    $cartItemData['myCustomData'] = $member_saved;
    return $cartItemData;
}, 10, 3 );

add_filter( 'woocommerce_get_cart_item_from_session', function ( $cartItemData, $cartItemSessionData, $cartItemKey ) {
    if ( isset( $cartItemSessionData['myCustomData'] ) ) {
        $cartItemData['myCustomData'] = $cartItemSessionData['myCustomData'];
    }
    return $cartItemData;
}, 10, 3 );
  1. Show the data in the cart and checkout page
add_filter( 'woocommerce_get_item_data', function ( $data, $cartItem ) {
    if ( isset( $cartItem['myCustomData'] ) ) {
        $data[] = array(
            'name' => 'Member saved',
            'value' => $cartItem['myCustomData']
        );
    }

    return $data;
}, 10, 2 );