select="*/tbody/row[position() mod $grp-size=1].

And this expression looks a little fishy since $grp-size=1 will return a boolean value which is probably not a meaningful argument for "mod".

Eliot's other comments are all valid but this one's wrong, I think. The
"mod" operator has higher precedence than "=". Mind you, it would probably
be worth writing it as

[(position() mod $grp-size) = 1]

so that other people reading your code don't make the same mistake.

Eliot
--
Eliot Kimber
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