Display variation name and its quantity in WooCommerce products management page (table version)

functions.php

<?php
add_filter( 'manage_edit-product_columns', 'woocommerce_product_custom_columns' );
function woocommerce_product_custom_columns( $columns ) {

    $new_columns = array();

    foreach ( $columns as $key => $value ) {
        $new_columns[ $key ] = $value;

        // Add total variations column after stock status column
        if ( $key === 'is_in_stock' ) {
            $new_columns['total_variations'] = __( 'Variations', 'woocommerce' );
        }
    }

    return $new_columns;

}

add_action( 'manage_product_posts_custom_column', 'woocommerce_product_custom_columns_value', 30, 2 ); // lower priority, so that we can display stock quantity after the stock status
function woocommerce_product_custom_columns_value( $column, $product_id ) {

    $product = wc_get_product( $product_id );

    if ( $column === 'total_variations' ) {
        if ( $product->is_type( 'variable' ) ) {
            $total_variations = count( $product->get_children() );
            printf( _n( '%d Variation', '%d Variations', $total_variations, 'woocommerce' ), $total_variations );

            $available_variations = $product->get_available_variations();
            $total_stock_quantities = 0;

            if ( !empty( $available_variations ) ) :
            ?>
                <br>
                <br>
                <table class="wp-list-table widefat fixed">
                    <thead>
                        <tr>
                            <th style="border-bottom: 1px solid #c3c4c7 !important;"><strong><?php esc_html_e( 'Variation', 'woocommerce' ); ?></strong></th>
                            <th style="width: 60px; border-bottom: 1px solid #c3c4c7 !important;"><strong><?php esc_html_e( 'Quantity', 'woocommerce' ); ?></strong></th>
                        </tr>
                    </thead>
                    <tbody>
                        <?php
                        foreach ( $available_variations as $variation ) :
                            $product_variation = new WC_Product_Variation( $variation['variation_id'] );
                            $total_stock_quantities += $product_variation->get_stock_quantity();
                            ?>
                            <tr>
                                <td><?php echo $product_variation->get_formatted_name(); ?></td>
                                <td><?php echo $product_variation->get_stock_quantity() ?: '–'; ?></td>
                            </tr>
                        <?php endforeach; ?>
                    </tbody>
                    <tfoot>
                        <tr>
                            <td><strong><?php esc_html_e( 'Total Quantity', 'woocommerce' ); ?></strong></td>
                            <td><strong><?php echo $total_stock_quantities; ?></strong></td>
                        </tr>
                    </tfoot>
                </table>
            <?php
            endif;
        } else {
            echo '–';
        }
    }

}