Would this be able to charge a micro usb powered laptop while its being used like the Surface 3?
Probably not, laptops need a lot more amps/watts to run.
This one can do a maximum of 2A by 5V = 10W
Check your laptop charger to see what it can do... for example my Acer laptop needs 3.42A and my MacBook Retina needs 20V and 4.25A giving 85W