If you have the Microsoft Office Integration enabled on your Asset Bank you will be able to preview Excel, PowerPoint and Word documents from within Asset Bank.
There are however limitations to this. Excel documents larger than 5mb and PowerPoint and Word documents larger than 10mb cannot be previewed using this integration. This is a design decision taken by Microsoft rather than a limitation of the Asset Bank software.
Files larger than these limits will need to be downloaded and opened in your computer's native Office products.