I could live with this, at least it is much better than a size that
depends on something *inside* the table, but my intuition is slightly
different. I've always found it difficult to specify the correct em,
for example in TeX: {\bf bold\quad} is different from {\bf
bold}\quad. In my style sheet proposal I've standardized on a single
em, namely the em of the document's default font.
In my view, every document has a normal font, even if that font is
never actually used. All sizes and styles are given relative to that
font: footnotes are two sizes smaller, headers two sizes larger and
bolder, etc. Table sizes should also be given in this measure. For, if
you specify a size at all (as opposed to automatic sizing), it is
because you want the table to look good relative to the rest of the
document.
For on-line presentation a size that is relative to the window size
may occasionally be useful, but giving a size in absolute units
(pixels, mm) is surely of very little use.
Bert
-- Bert Bos Alfa-informatica <bert@let.rug.nl> Rijksuniversiteit Groningen <http://www.let.rug.nl/~bert/> Postbus 716, NL-9700 AS GRONINGEN