I'm dealing with a 500 page book (if you give me your github username, I'll happily add you to the repo) and many of these problems emerge only at scale. (when I render individual chapters, there are no issues, but when rendering the whole book, the tables just have all sorts of formatting issues.)

Here's a working example

% engine=luajittex
\startenvironment env_trap
\enableregime[utf-8]  
\setupcolors[state=start]
\setupreferencing[autofile=yes]
\setupinteraction[state=start, color=blue, contrastcolor=blue, style={\tf}]
\usemodule[simplefonts]

\usemodule[database]
% Enable hyperlinks

\setuppapersize [A4][A4]
\definepapersize[standing][A4][A4]
\definepapersize[lying][A4,landscape][A4]
\setuplayout    [width=middle,  backspace=.75in, cutspace=.75in,
                 height=middle, topspace=.5in, bottomspace=.5in]

\setupbodyfont[11pt]

\setupwhitespace[none]

\setupcaption[table][location=top]
\setupcaptions[style={\tfx}, width=.9\textwidth,align=middle]

   \unprotect
   \appendtoks
     \setupbackgrounds[\v!page][\c!background=\makeupparameter\c!background]
   \to \t_page_makeup_every_setup
   \protect


\defineseparatedlist[CSV]
  [separator={,},
   quotechar={"},
   left=\bTD,right=\eTD,
   first=\bTR,last=\eTR,
   before=\bTABLE,after=\eTABLE]


\setupTABLE[c][each][align=flushleft,style={\tfx},width=fit]
\setupTABLE[r][1][background=color,backgroundcolor=gray,style={\tf}]
\setupTABLE[align=middle]
\setuppagenumbering[alternative=doublesided]

\stopenvironment

\starttext

\placetable[here][tab01]{Kazanlak site numbers, aggregate area and average area
through through time}{
\setupTABLE[c][each][align=middle,style={\tfx},alignmentcharacter={.},aligncharacter=yes]
\chardef\characteralignmentmode=2
\startCSV
Period,NL,Chl,EBA,LBA,EIA,LIA,RM,LA,BYZ,MA,OTT
Aggregate Area (ha),1.5,2.9,5.0,6.7,21.5,43.3,54.9,31.2,24.4,30.7,94.9
Site Count,3,6,10,7,23,38,23,19,15,21,15
Avg Area (ha),0.5,0.5,0.5,1.0,0.9,1.1,2.4,1.6,1.6,1.5,6.3
\stopCSV
}

\stoptext

And I wasn't able to cause it to fail via a trivial 'making it a component' and calling it from a project. 

 
------------------------------

Message: 5
Date: Mon, 18 Apr 2016 22:11:28 +0200
From: Hans Hagen <pragma@wxs.nl>
To: ntg-context@ntg.nl
Subject: Re: [NTG-context] Table index is nil
Message-ID: <57153F70.6050505@wxs.nl>
Content-Type: text/plain; charset=utf-8; format=flowed

On 4/18/2016 3:59 AM, Brian Ballsun-Stanton wrote:
> I'm getting (suddenly) an error:
> ...ext/tex/texmf-context/tex/context/base/mkiv/font-hsh.lua:124: table
> index is nil
>
>
> And I have a bunch of tables:
>
>
> \placetable[here][tab01]{Kazanlak site numbers, aggregate area and
> average area
> through through time}{
> \setupTABLE[c][each][align=middle,style={\tfx},alignmentcharacter={.},aligncharacter=yes]
> \chardef\characteralignmentmode=2
> \startCSV
> Period,NL,Chl,EBA,LBA,EIA,LIA,RM,LA,BYZ,MA,OTT
> Aggregate Area (ha),1.5,2.9,5.0,6.7,21.5,43.3,54.9,31.2,24.4,30.7,94.9
> Site Count,3,6,10,7,23,38,23,19,15,21,15
> Avg Area (ha),0.5,0.5,0.5,1.0,0.9,1.1,2.4,1.6,1.6,1.5,6.3
> \stopCSV
> }
>
> The odd thing is that no other chapters of the book (all of which use
> the same environment, and many use the same table)
>
> When I comment out the series of tables, the errors go away.
> I've just rerun first-setup.sh just out of paranoia. mtx-context     |
> current version: 2016.04.17 11:56

i really need a small *working* example for this