An accessible table

This is just an example of what you can do to make a data table accessible to screen readers used by the blind or visually impaired user. Each column heading is given an id, and then cells in the table body are identified as being in a given column via the header id. Eg.

A snippet of the html code showing column headers being given ids and these being referenced in cells.

Copernican/modern Sun/planet distances
Planet	Copernican value (AU)	Modern value (AU)
Mercury	0.38	0.39
Venus	0.72	0.72
Earth	1.00	1.00
Mars	1.52	1.52
Jupiter	5.22	5.20
Saturn	9.07	9.55
Uranus	-	19.19
Neptune	-	30.07
Pluto	-	39.54

Source: Universe: Stars and Galaxies 2nd edition Freedman & Kaufmann table 4-2 p68