It should work when the caret is in one of these lines. I guess it should really have worked in the line before them as well, I'll need to check the regexp for that. It works once the scope is meta.cell.environment.tabular.latex I'll change it to be meta.row.... and then it should work in the previous line as well, though it still won't work if you are in the \begin{tabular} line.
\textbf{Answer} & \textbf{Average} & \textbf{Standard Deviation}\
\hlx{vhv} text text text & \num{4.1} & \num{1.5} \ \hlx{vhv}
Haris