Need safe power supplies for beginner class with indicator light
If you wanted to roll your own you could do it with a transformer, a full-wave bridge rectifier, a reservoir capacitor, a 7812 and a 7805, like this:



The regulators are self-protecting against overloads, so LEDs showing overcurrent would only be for the benefit of the students, but could certainly be added if desired.

Assuming a 12 volt RMS output for T1, C1 would charge up to about 17 volts, DC, which would put 5 volts across the 7812.

Then, a 200 mA load on the 12 volt line and a 200 mA load on the 5 volt line would mean the current through the 7812 would be 400 mA and it'd be dissipating: \$ \text{0.4A}\times\text{5V} = \text{ 2 watts,}\$ which means you'd need a heat sink on it to keep it from going into thermal overload. 
With 12 volts on the input of the 7805 and a 200 mA load on it, it'd be dissipating 1.4 watts, so it would need a heat sink as well.

Update:

Per your your comment requesting one transformer and four regulators per table, here's a way to go about it:

 

I've only shown two regulator stages, for convenience,  but any number can be implemented by sizing the transformer properly.