The load regulation is the % change in output voltage, normally full load vs unloaded. For example, if the output voltage is 10V and the load regulation is 1%, the maximum change in voltage, between full and no load, is 10*0.01 = 0.1V.
In short, those AC:DC converter board are regulated. Another sign of this is the wide input voltage range. Unregulated converters specifiy a tight input voltage range.