I agree with David. I have seen many teams tape their practice mats for convenience -- some as he mentioned, some with double-sided tape under the corners, some with dual-lock. But, it is important that the kids understand the potential variables for the mats at the tournaments.
We saw just about everything at the different tournaments over the last eight years -- some unfolded the mats the night before and they still had folds sticking up, some did not align the mat "correctly" or the table dimensions weren't what was "expected", some had cracks or un-level sections under the mat, and somehow they all taped down the mats differently.
For eight years, our team did not have a permanent practice space so we found using no tape, rolling the mat, and storing it in a tube or box was the safest method for transport and easy enough that the kids could do it themselves. The looser the roll, the sooner it sits flat. One benefit was that it forced the kids to know the proper field setup.
We tried several different tables over the years. The collapsible/travel tables will force you to re-align you mat each time so installing and removing tape is going to end up destroying your mat.
This is a good team engineering project for the kids!
Good luck!
Jeff Beima