Use natural tables, they provide better control about the cell size and layout.
Wolfgang, thanks! I wasn't aware of them. They don't seem to have found their way into contextref.pdf I could do what I want and more! Below is the solution for my situation. Gleened from http://wiki.contextgarden.net/TABLE and the docs referenced on that page. Martin \setupTABLE[column][width=4cm] \setupTABLE[column][1][width=1cm] \setupTABLE[row][align={middle,lohi},height=6ex] \bTABLE \bTR \bTD Std \eTD \bTD Montag \eTD \bTD Dienstag \eTD \bTD Mittwoch \eTD \bTD Donnerstag \eTD \bTD Freitag \eTD\eTR \bTR \bTD 1 \eTD \bTD[nr=2] mo \eTD \bTD[nr=2] di \eTD \bTD[nr=2] mi \eTD \bTD frei \eTD \bTD frei \eTD \eTR \bTR \bTD 2 \eTD \bTD do \eTD \bTD fr \eTD \eTR \bTR \bTD 3 \eTD \bTD mo \eTD \bTD di \eTD \bTD mi \eTD \bTD do \eTD \bTD fr \eTD \eTR \eTABLE