Your home AC system uses circuits. You can have all the outlets of 2 rooms on a single circuit, the number of outlets or even the number of devices pluged into that circuit does not truley mean anything.
What matters is the amount of amps being pulled from the circuit. Most homes either have a 15 or 20 amp breaker in the fuse panel. If your computer is pluged into the same circuit (outlets connected to a single fuse) that has an electric motor like an air compressor, a winow air conditioner, running a vacumm, or other high amp items then there could be an issue, but for the most part that would only result in poping the AC breaker and not affecting system performance.
Also the electrical system does not care about what is on a surge protector vs what is pluged in straight to the outlet, in regards to load it is all the same.
The computer/devices on the other hand does care if it is on a surge protector as the surge protector cleans dirty power and regulates spikes.
The "2 for $5 special" surge protectors are not rated to handle 1000w psus plus a bunch of other stuff, but any decent surge protector will handle your 650w computer, + monitor(s), + printer and any other normal office appliance.