Example of custom registration add to cart template, displaying registrations details in a table.

registration.php

<?php
/**
 * Registration product add to cart
 * Put this file in your theme under woocommerce/single-produt/add-to-cart
 *
 * @author  Allyson Souza
 * @package Registrations for WooCommerce/Templates
 * @version 1.0.0
 */

 if ( ! defined( 'ABSPATH' ) ) {
 	exit;
 }

 global $product;

 $attribute_keys = array_keys( $attributes );

 do_action( 'woocommerce_before_add_to_cart_form' ); ?>

 <?php if ( empty( $available_variations ) && false !== $available_variations ) : ?>
     <p class="stock out-of-stock"><?php _e( 'This product is currently out of stock and unavailable.', 'woocommerce' ); ?></p>
 <?php else : ?>
     <table class="registrations table table-striped table-hover table-bordered table-responsive-vertical" cellspacing="0">
             <thead>
                 <tr>
                     <td>
                         <?php _e( 'Class', 'my-text-domain' ); ?>
                     </td>
                     <td>
                         <?php _e( 'Day of Week', 'my-text-domain' ); ?>
                     </td>
                     <td>
                         <?php _e( 'Dates', 'my-text-domain' ); ?>
                     </td>
                     <td>
                         <?php _e( 'Schedule', 'my-text-domain' ); ?>
                     </td>
                     <td>
                         <?php _e( 'Available Seats', 'my-text-domain' ); ?>
                     </td>
                     <td>
                         <?php _e( 'Choose the quantity', 'my-text-domain' ); ?>
                     </td>
                 </tr>
             </thead>
             <tbody>
    <?php do_action( 'woocommerce_before_variations_form' );
    $count = 0;
    ?>
			<?php foreach ( $attributes as $attribute_name => $options ) :
                foreach ( $options as $option ) : ?>
                    <form class="registrations_form cart" method="post" enctype='multipart/form-data' data-product-id="<?php echo absint( $product->id ); ?>" data-product-variations="<?php echo esc_attr( json_encode( $available_variations ) ) ?>">
                        <tr>
                            <td data-label="Class" class="registration-id">
                                <?php echo $available_variations[ $count ]['variation_id'] ; ?>
                            </td>
                            <td data-label="Days of Week" class="registration_week-days">
                                <?php $product->registration_days_of_week( $available_variations[ $count ]['variation_id'] ); ?>
                            </td>
                            <td data-label="Dates" class="registration_date">
                                <?php $product->registration_date( $available_variations[ $count ]['variation_id'], 'd \d\e F \d\e Y' ); ?>
                            </td>
                            <td data-label="Schedule" class="registration_schedule">
                                <?php $product->registration_schedule( $available_variations[ $count ]['variation_id'] ); ?>
                            </td>
                            <td data-label="Available Seats" class="registration_availability">
                                <?php echo $available_variations[ $count ]['max_qty']; ?>
                            </td>
                            <td class="register" data-label="Choose the quantity">
                                <?php do_action( 'woocommerce_before_add_to_cart_button' ); ?>
                                <div class="single_variation"></div>
                                <div class="variations_button">
                        			<span class="quantity input-group">
                                        <input step="1" name="quantity" value="1" title="Qtd" class="input-text qty text form-control" size="4" type="number" min="1" max="<?php echo esc_attr( $available_variations[ $count ]['max_qty'] ); ?>">
                            			<span class="input-group-btn">
                                            <button type="submit" class="single_add_to_cart_button btn btn-action btn-success alt"><?php _e( 'Inscreva-se', 'abelman' ); ?></button>
                                        </span>
                                    </span>
                        			<input name="add-to-cart" value="<?php echo absint( $product->id ); ?>" type="hidden">
                        			<input name="product_id" value="<?php echo absint( $product->id ); ?>" type="hidden">
                        			<input name="variation_id" class="variation_id" value="<?php echo $available_variations[ $count ]['variation_id']; ?>" type="hidden">
                        		</div>
                                <input type="hidden" value="<?php echo esc_attr( $option ); ?>" id="<?php echo sanitize_title( $attribute_name ); ?>" class="" name="<?php echo 'attribute_' . sanitize_title( $attribute_name ); ?>" data-attribute_name="<?php echo 'attribute_' . sanitize_title( $attribute_name ); ?>">
                            </td>
     					</tr>
                        <?php do_action( 'woocommerce_after_variations_form' ); ?>
                    </form>
                 <?php
                    $count++;
                    endforeach;?>
        <?php endforeach;?>
		            </tbody>
	             </table>
 			<?php
 				/**
 				 * woocommerce_before_single_variation Hook
 				 */
 				//do_action( 'woocommerce_before_single_variation' );

 				/**
 				 * woocommerce_single_variation hook. Used to output the cart button and placeholder for variation data.
 				 * @since 2.4.0
 				 * @hooked woocommerce_single_variation - 10 Empty div for variation data.
 				 * @hooked woocommerce_single_variation_add_to_cart_button - 20 Qty and cart button.
 				 */
 				//do_action( 'woocommerce_single_variation' );

 				/**
 				 * woocommerce_after_single_variation Hook
 				 */
 				//do_action( 'woocommerce_after_single_variation' );
 			?>
 		</div>

 		<?php //do_action( 'woocommerce_after_add_to_cart_button' ); ?>
 	<?php endif; ?>

 <?php do_action( 'woocommerce_after_add_to_cart_form' ); ?>