Many thanks for the suggestion Vit.  In this case, however, I've split the \starttable and \stoptable commands in the \startAuthors and \stopAuthors definitions which may well be the root of my problem.  This means that I cannot easily wrap the whole table with \placeongrid{ }.  I cannot see a way of getting the \domoveongrid and/or \snaptogrid\vbox to work either.

Does anyone have any suggestions on how I can clean this up so that \starttable and \stoptable are not in separate definitions but I can still use variables to define the table elements as is done in the \Authors definition?

Cheers,
Randall
 
\placeongrid{%    or e.g. \placeongrid[{broad,high}]{%
   your table
}
> %%% Authors and Approvals
> \def\AuthorsTitle{\midaligned{\sc{Authors and Approvals}}}
>
> \def\startAuthors{%
>   \blank[2*big]\AuthorsTitle\\\blank[2*big]%
>   \hbox to \hsize\bgroup\hss\SetTableToWidth{ 6.5in}%
>   \starttable[|c|c|c|c|c|]
>   \HL
>   \VL \VL Function\VL Name\VL Signature\VL Date\VL\SR\HL}
>
> \def\stopAuthors{\stoptable\hss\egroup}
>
> def\Author[#1]{%
>   \getgparameters[Author][#1]%
>   \doifundefined{AuthorRole}{\gdef\AuthorRole{Prepared by:}}%
>   \doifundefined{AuthorFunction}{\gdef\AuthorFunction{-}}%
>   \doifundefined{AuthorName}{\gdef\AuthorName{-}}%
>   \doifundefined{AuthorSignature}{\gdef\AuthorSignature{}}%
>   \doifundefined{AuthorDate}{\gdef\AuthorDate{-}}%
>   \VL\AuthorRole \VL\AuthorFunction%
>   \VL\AuthorName \VL\AuthorSignature%
>   \VL\AuthorDate%
>   \VL\SR\HL%
>   \gdef\AuthorFunction{ }\gdef\AuthorName{ }%
>   \gdef\AuthorSignature{ }\gdef\AuthorDate{ }%
>   }