version of email_order_items_table for use outside of the class

email_order.php

<?php
	$return = '';

	foreach( $order->get_items() as $item ) :

		$_product = $order->get_product_from_item( $item );

		$file = $sku = $variation = $image = '';

		$src = wp_get_attachment_image_src( get_post_thumbnail_id( $_product->id ), 'thumbnail');
		$image = apply_filters('woocommerce_order_product_image', '<img src="'.$src[0].'" alt="Product Image" height="100" width="100" style="vertical-align:middle; margin-right: 10px;" />', $_product);

		$item_meta = new WC_Order_Item_Meta( $item, $_product );
		$variation = '<br/><small>' . $item_meta->display( true, true ).  '</small>';


		$return .= '<tr>
			<td style="text-align:left; vertical-align:middle; border: 1px solid #eee;">'. $image . apply_filters('woocommerce_order_product_title', $item['name'], $_product) . $variation . '</td>
			<td style="text-align:left; vertical-align:middle; border: 1px solid #eee;">' . $item['qty'] .'</td>
			</tr>';

		// Show any purchase notes
		if ($purchase_note = get_post_meta( $_product->id, '_purchase_note', true )) :
			$return .= '<tr><td colspan="3" style="text-align:left; vertical-align:middle; border: 1px solid #eee;">' . apply_filters('the_content', $purchase_note) . '</td></tr>';
		endif;

	endforeach;
	echo $return;
	?>