I am not an EE, so please be gentle! I will obviously get a certified EE to review my design before anyone else touches this so please assume that I know enough to at least be safe with 120VAC and am comfortable with frying my own electronics :).
What I'm doing
You can follow that SRD-05VDC link to a datasheet about the relay module itself. While it's rated for 10A @ 125VAC for resistive loads, it's only rated for 3A @ 120VAC for inductive loads.
Since my application is for controlling a standard (US) AC outlet, I don't know what people might plug in (blenders, vacuums, leaf blowers, etc).
My question is about whether it would provide any additional inductive protection if I placed a TVS diode across the relay terminals? If so, what would be an appropriate diode to use for general household 120VAC applications?
If my question is dumb
If that's a bad idea in general, what would by an appropriate relay module to switch a general purpose 120VAC outlet using a 3-5V input signal?