There is currently no available port of OpenOffice.org or LibreOffice for Android. Android is very different from a traditional Linux distribution, so code written for one will not simply run on the other, despite the fact that they share some facets like a kernel.
There has been some work toward an Android version of LibreOffice, but it is not ready to be released yet. Ars Technica reported about a demo of the initial prototype.
There are, however, many other apps which will allow you to open and/or edit .xls files.