Talking about these holes!
I always use them for when i make little trumpet-shaped filler flowers - put a ball of fondant/gumpaste over one and then roll it out flat to make a wide-brimmed hat shape that can then be cut into petals. Not sure if that's what they're really for, though.
Thanks. Someone told me they are used for mexican hat flowers. So I guess yours makes sense. :)
LizzieAylet is correct, these can be used for Mexican hat flowers.
Here's some more info:
Some mats are reversible, holes on one side, no holes on the other side.