Positive electrode potential of copper
The potential as it is given there is vs. standard hydrogen electrode(SHE) which has an arbitrary assigned value of 0.0000V. Through the choice of another reference, it is very easy to make all of those numbers positive or negative. The absolute value of the half cell potential can only be useful in comparison to others. So you could make arguments like Cu has a more positive potential compared to Ni(by 0.59V based on the above numbers), but that is it.