As Indianatone told, Office needs to be installed on virtual machine if you want to open Office files on it.
What is quite often forgotten is that a virtual machine is like any other individual computer. It can and will not use the software, applications and AV protection of its host system. If you want to / need to open, create and edit Office files on both your host system and guest virtual machine, Office must be installed on both. That also requires two licenses.
My recommendation is and has always been to use free alternatives on virtual machines to avoid any license issues. For instance, if you have let's say licensed Norton AV and Ms Office 2010 on your host, use free MSE
on your virtual machines.