How to make a schedule voice recorder using Tasker + easy voice recorder?
After you start the recording which you've already figured out, but for others I'll list it below, you add a Wait action for the specified amount of time, then add an action to stop recording.

In your task, choose Plugin->Easy Voice Recorder and configure it to Record.  For the second action, choose Task->Wait and configure it for 10 hours.  For the final action, choose Plugin
->Easy Voice Recorder and configure it to Stop.

A1: Easy Voice Recorder Pro [ Configuration:Record Package:com.digipom.easyvoicerecorder.pro Name:Easy Voice Recorder Pro Timeout (Seconds):0 ] 
A2: Wait [ MS:0 Seconds:0 Minutes:0 Hours:10 Days:0 ] 
A3: Easy Voice Recorder Pro [ Configuration:Stop Package:com.digipom.easyvoicerecorder.pro Name:Easy Voice Recorder Pro Timeout (Seconds):0 ]