add_filter( 'sliced_invoice_line_items_output', 'sliced_display_woocommerce_line_items_20180213', 9, 1 );
function sliced_display_woocommerce_line_items_20180213( $output ) {

	$order = sliced_woocommerce_get_order();

	if( ! isset( $order ) || $order == false || empty( $order ) )
		return $output;

	$output = null;
	$output = '<table class="table table-sm table-bordered table-striped">
		<thead>
			<tr>
				<th class="qty"><strong>' . __( "Hrs/Qty", "sliced-invoices" ) . '</strong></th>
				<th class="service"><strong>' . __( "Service", "sliced-invoices" ) . '</strong></th>
				<th class="sku"><strong>' . __( "SKU", "sliced-invoices" ) . '</strong></th>
				<th class="rate"><strong>' . __( "Rate/Price", "sliced-invoices" ) . '</strong></th>';
				$output .= '<th class="total"><strong>' . __( "Sub Total", "sliced-invoices" ) . '</strong></th>
			</tr>
		</thead>
		<tbody>';

		foreach( $order->get_items() as $item_id => $item ) {

			$class = ($count % 2 == 0) ? "even" : "odd";

			$product = apply_filters( 'woocommerce_order_item_product', $order->get_product_from_item( $item ), $item );
			$purchase_note = get_post_meta( $product->get_id(), '_purchase_note', true );

			$is_visible = $product && $product->is_visible();

			$output .= '<tr class="row_' . esc_attr( $class ) . ' sliced-item">';

				$output .= '<td class="qty">' . apply_filters( 'woocommerce_order_item_quantity_html', ' <strong class="product-quantity">' . sprintf( '%s', wp_kses_post( $item['qty'] ) ) . '</strong>', $item ) . '</td>';

				$output .= '<td class="service">' . apply_filters( 'woocommerce_order_item_name', $is_visible ? sprintf( '<a href="%s">%s</a>', get_permalink( $item['product_id'] ), $item['name'] ) : $item['name'], $item, $is_visible ) . '</td>';

				$output .= '<td class="sku">' . $product->get_sku() . '</td>';

				$output .= '<td class="rate">' . wp_kses_post( wc_price( $order->get_item_subtotal( $item ) ) ) . '</td>';

				$output .= '<td class="total">' . wp_kses_post( $order->get_formatted_line_subtotal( $item ) ) . '</td>';

			$output .= '</tr>';

		$count++;
		}

	$output .= '</tbody></table>';

	return $output;
}