I tested this on the online context tool, and the tabulate repeats header in MKii, but doesn’t in MKiv. Have the settings changed in MKiv, or is the functionality not there yet?
 
-Lance Larsen
 
 
Date: Tue, 30 Apr 2013 14:08:44 -0700
From: "Lance Larsen" <lance.c.larsen@gmail.com>
To: <ntg-context@ntg.nl>
Subject: [NTG-context] Header not repeating for tabulate
Message-ID: <518032de.6dd2440a.6573.04f0@mx.google.com>
Content-Type: text/plain; charset="us-ascii"

I created a table using tabulate. I want the header to repeat, and used the
following code. The table splits correctly, but the header doesn't repeat.
Any idea why the header doesn't repeat?

\setuptabulate[split=yes,header=repeat]
\starttabulatehead
\HL
\NC  \bf  Variable     \NC     \bf Value  \NC    \bf Reference        \NR
\HL \HL
\stoptabulatehead
\starttabulate[|lw(1in)|lw(1in)|l|]
\dorecurse{100}{\NC  Column 1 value \NC  Column 2 value \NC  Ref. Column 3
value  \NC \AR} \stoptabulate