If you are running Windows 10 inside VirtualBox, you may want to enable copy/paster from windows and vice versa. This tutorial should work on any other Windows version also. Here are steps to enable copy/paste on a virtual machine in VirtualBox on Mac. Note that these settings can be changed when machine is in any mode (shutdown or running).
Select virtual machine settings for Windows 10 machine.
Select general settings, click on advanced tab and locate shared clipboard select box.
Change shared clipboard value to “bidirctional” and click ok. After this copy paste should work from Mac to VirtualBox windows session and vice versa.