threeparttable \midrule-sized space

Question

I want to add some space between rows of my threeparttable. One way is to add \midrules, but that adds lines which are visually confusing. Is there a \midspace command?

Side question: Is threeparttable the best table to use in memoir?

Answer 1

The booktabs package provides \addlinespace, which by default adds a space equal to that of \midrule.

\documentclass{article}

\usepackage{booktabs}

\begin{document}

\begin{tabular}{cc}
\toprule
letter & number \\
A & 1 \\
B & 2 \\
\midrule
C & 3 \\
\addlinespace% adds \defaultaddspace (by default 5pt)
D & 4 \\
\addlinespace[3pt]
E & 5 \\
\bottomrule
\end{tabular}

\end{document}

In case you didn't know: The booktabs manual is a must read on "how to build typographic pleasant tables" (Sveinung).

Answer 2

You can add vertical space in the optional argument of the \\ command:

\begin{tabular}{l}
test \\
test \\[\smallskipamount]
test
\end{tabular}

\smallskipamount, \medskipamount and \bigskipamount are predefined lengths that are used by \smallskip, \medskip and \bigskip vertical spacing commands. Of course, you can also specify any other length in the optional argument.

Using (not too big) vertical space to separate parts of a table should be typographically fine. But, IMO, rules should be preferred for caption rows or "total" rows.