title: EPPlus multi-threading gets "out of memory" exception
body: <p>I was trying to parallelize EPPlus by using multi-threading. I tried to spawn 20 threads with each thread generating 1000 sheets with 10 column and 26 rows. The program consumed memory up to 1.8GB and threw an "out of memory" exception. </p>
  
  <p>Does anyone know how to solve this?</p>
  
  <p>Thank you. </p>