BEIJING—Japanese automakers Honda Motor Co., Nissan Motor Co., and Toyota Motor Corp.’s sales in China tumbled again in October as a microchip shortage hit vehicle production in the world’s biggest car market. Honda said it sold 148,377 vehicles in China last month, down 18 percent from a year earlier, while Nissan said it sold 113,876 cars, down 22 percent. Toyota said it sold 142,000 cars in China last month, down 19 percent.