I'm currently working with Nathan Hurst on improving table layout: how to choose column widths & row heights that minimize wasted space (or get more readability from a given amount of space).
The HTML standard includes one specification of how this is to be done, though its results are in many cases displeasing.
It may be difficult to get improvements into newer HTML standard (given the number of browsers needing updating), though we may well be able to use the improved approach in software that isn't bound by standards for table layout, e.g. word processors and spreadsheets. ("Word processors" could even include HTML editors: the HTML editor could give hinted row/column sizes as percentages if the user was unhappy with the default assignment given by the HTML algorithm.)
I'm quite happy with the improvements we've made, but I'd like more ideas about how to have these improvements used.