So far as tables go, I would look at the data model behind XBRL.
XBRL is sometimes maligned and often misunderstood, but essentially it is a format for presenting multi-dimensional tabular information. It is not really specific to finance, but financial reports really are hypercubes so it fits that domain.
A wikified model would take more work, but it may be the way to go.
One beef I have with time series data from the world bank is that many of them are piece-wise linear interpolated but don't document this. A geometric interpolation would be more plausible for one thing, but you see no bend in the curve caused by the '67 war in Nigeria, and no evidence that experts think the the eye-popping population numbers for Nigeria are a bit high.
All of this matters little if you are doing a demo, but if you really care what the population of Nigeria is, this is a problem.