There are a number of tools such as DataTables which provide enhanced access to HTML tables for Javascript capable browsers. However, these tools often lack keyboard accessibility. KeyTable addresses this by allowing Excel like cell navigation on any table.
KeyTable is a Javascript library which provides keyboard navigation and event binding for any HTML table. With KeyTable Excel style table navigation can be employed to provide features such as editing of a table without requiring a mouse. Simply navigate to the cell you wish to edit and hit return. This initialises the excellent jEditable plug-in for jQuery - make your edit and then hit return again to save.
Requirements: IE 6+, Firefox 3+, Safari 3+, Opera 9.6
Demo: http://www.sprymedia.co.uk/article/KeyTable
License: GPL or BSD License