How do you perforate a teflon sheet?
You should contact a specialized company, however you should also provide more infos about the diameter and the number of the holes you want. This is an excerpt from FedTech: 


  laser cutting is the method of choice for small perforation, as laser
  cutting has a smaller, tighter cutting tolerance and thus has the
  capability to create tiny, intricate perforations. However, if you
  prefer, abrasive waterjet cutting can be used as well but for larger
  perforation (.030" and up, respectively). If you prefer to use
  non-abrasive waterjet cutting, you can create perforations up to .004"
  in diameter, however this form of waterjet cutting is restricted in
  cutting certain types of material. With non-abrasive waterjet cutting,
  you can cut up to about 12" thick from the following: plastic, rubber,
  foam, composites, silicone, foam, felt, cork, Teflon (PTFE), neoprene,
  and other soft materials