Teradyne Inc., Boston, said it is laying off about 150 of its 5,000 employees due to a slowdown in orders. About 30 employes at the firm's Woodland Hills division will be affected . . . A Manhattan judge ruled that Consumers Union magazine cannot prevent Remington Products from advertising that the magazine gave a high rating to Remington's electric shaver . . . Datapoint confirmed that a previously announced cost-reduction program will be implemented in the near future.