Hi Siddharth,
These files contain CPU utilization values measured every 5 minutes in PlanetLab's VMs. CloudSim includes a class called UtilizationModelPlanetLabInMemory, which can be used to read those workload traces. You just need to supply the path to a workload trace file when creating an object of the class, and it will automatically read the data from the file. Next, you need to pass the created object to a Cloudlet object and send it to a VM. Once given resources, this Cloudlet will generate the CPU utilization according to the provided CPU utilization trace.
Best regards,
Anton