XLR format is rarely supported in modern spreadsheet programs and was originally used in Microsoft Works. You will have hard time working or exporting them without the original program, although quite many people are looking for xlr to pdf conversion.
If you do no have access to old MS Works and cannot find installation discs, then maybe older versions of Excel could be helpful as before Works was discontinued, its files were supported in MS Office just fine. However, latest version of Excel does not support this file type anymore.Open XLR file Open PDF file
A popular spreadsheet application distributed with Microsoft Office suite
A popular spreadsheet application from the Microsoft Office suite