I find these are often rated say around 250v &10A according to the manufacturers.
Having said that these ratings can often look exaggerated on cheaper Chinese gear. Whats important here is that the terminal blocks, the actual relay unit and the PCB trace between them can handle the load. Oven on these sorts of boards you see the trace has been bulked out with more solder.
I don't think 10a @ 250v is that unbelievable on these sorts of boards but the temperature is always a good indicator of how its actually performing under load.