I don't know if there is such functionality on it, but if you need a free wave editor you can use audacity.
http://audacity.sourceforge.net/
The best way to avoid clicks on loops is making a fast fade-in and/or fade-out (approx 20ms) on the sample.
This usually works good for beat loops.
Sampling instruments is more a pain in the neck, because in theory you have to match the end value of the sound loop with the beginning value.
A way to sample instruments loops is recording a cross-fading loop three times and then get the second one to make the sample.
In this case the cross-fade data of the sample is the same at the beginning and the end of the sample.
Having a loop-start point and the EG available also in loop mode would be great to create perfect sampled instruments, I will never understand why they didn't put them on this gear to make it almost perfect...
Another technique from the '90s (don't tell me, I know, I'm old!) that was automatic in some samplers like the Roland W-30, is creating a loop that play the sample forward and then backward.
In this way the start and end point of the loop are perfectly the same and you don't get clicks, of course sometimes it works sometimes doesn't...
Hope it helps!