(On that note: when you add table support to a markup language PLEASE support newlines and paragraphs inside table cells. Don't assume that all tables are spreadsheets with only a small amount of text per cell. Some of us live in tables like high-rise apartments, eg bug tracking, school note taking & image stacking in cells.)
If it's non-numeric data and needs to be in tables the best program I've found is treesheets. Absolutely brilliant program.
Indeed it still seems a bit limited. Nothing like Firefox's in-built table editor used to be (this is the one in Thunderbird, which is quite nice). I wish they hadn't removed that feature :|
Treesheets is a beautiful program, but I'm too much of a pen-and-paper + plaintext notes person to appreciate it properly.