# Vertical space between two tables

When doing something like this:

\begin{longtable}{llll}
% Stuff here
\end{longtable}

\begin{longtable}{llll}
% Stuff here
\end{longtable}


What command (I don't know the name of those, I mean like footskip, topmargin, etc.) takes care of the space between the two tabulars in this case? I would like to avoid putting a \vspace here, I don't like to fight with LaTeX, I always lose. :) I would like to reduce the vertical spacing.

longtable does \vspace{\LTPre} before a table and \vspace{\LTpost} after a table, both of which are by default \bigskipammount.
Most latex display environments use \addvspace to add their vertical offsets, so that adjacent spaces combine (\addvspace just adds the maximum of any space currently on the vertical list and the space requested) but longtable doesn't do that so you get twice the space you would get from \bigskip between the tables unless you have set \LTpre or \LTpost to something else.