Just a quick note that I pushed TableField 2.0 for Drupal 6. The major new feature is the ability to upload CSV files to your tables. There are also a slew of UI and CSS bug fixes. Thanks to everyone who submitted issues!
In case you haven't tried it, TableField is a CCK widget that lets you attach simple tabular data to your nodes. There is also a 7.x version that lets you attach tables to any entity like nodes, taxonomy terms, etc.