Every appliance has a electronic signature that runs back thru the power lines, YES they can tell what you have plugged into the wall and if it's turned on.
A way to get around this is to use a Line-Conditioner UPS between your wall and your lights etc, the L-C UPS smooths out any power surges or drops coming out of your wall and stops any electronic signatures going back out the wall to the meter, of course this wont stop your usage showing up if it's HIGH and constant power draw @ 12/12 or 18/6. You can run flip-flops or slightly change your timers by half an hour backward and forward so the power draw isn't exactly the same time every day and stops at the same time every day
A way to get around this is to use a Line-Conditioner UPS between your wall and your lights etc, the L-C UPS smooths out any power surges or drops coming out of your wall and stops any electronic signatures going back out the wall to the meter, of course this wont stop your usage showing up if it's HIGH and constant power draw @ 12/12 or 18/6. You can run flip-flops or slightly change your timers by half an hour backward and forward so the power draw isn't exactly the same time every day and stops at the same time every day