Excel for Mac 2011 – requirements

Taken from the Mac:Office download store

Required Processor 
A Mac computer with an Intel processor
Required Operating System
Mac OS X version 10.5.8 or later
Recommended Memory
1 GB of RAM recommended
Required Hard Disk Space
2.5 GB of available hard disk space
Required Media Drive
DVD drive or connection to a local area network (if installing over a network)
Other System Requirements
HFS+ hard disk format (also known as Mac OS Extended or HFS Plus)

Additionally, you will need a full installation, with vba enabled.