Tape would be a good idea. I wonder if a couple of well placed thick carpet-pads would work to hold it down. We have some of those holding down rugs on a wood floor and they work really well.

Edit: norsk website actually says just put it on the floor. The use of an adhesive or other backing isn't advised.

Slipperiness is considered. I may put down some double sided tape or maybe a small dab of construction adhesive on a few of the tiles. Something to give it a bit of shear strength. They will be going wall to wall in one direction so I'm hoping that they'll have some structure that way.