torontodan:
My TP-link smartplug is rated for 15A at 110VAC. I have the North American three-prong plug type. You should be able to plug most of your computer equipment in without exceeding that load. 15A is about what a portable electric heater consumes. However:

If you turn off your computer with the Smartplug, it will crash your OS. If you shut the computer down, it somewhat defeats the purpose. If you turn off many inkjet printers without using the printer power switch, the printer may not park the heads and they may dry out, needing expensive replacement. You could turn off speakers, the monitor and lights with the smart plug. Any decent power strip should be suitable. However, most strips come with a switch, so unless you need to automate the shutdown, you might do better to just flip the switch.

The Smartplug is a versatile unit. I would recommend you find a more valuable use for your Smartplug; have it turn on a light in your house at sunset, for instance, and turn it off at say midnight. Plug a fan into it, and fall asleep to a gentle wind and have it turn off after your asleep.

You are, of course, free to enjoy your Smartplug however you wish :-)