Changing dimensions (height and width ) of latex table generated tabularray

Question

I need to make the LaTeX table generated here smaller in height either by changing the total height or each row height, whichever looks better. How can I do that? Here is the code:

\begin{table}[h!]
\centering
\caption[Transformation table]{Transformations generated by Mach et al. Y in a dark cell: highly recommended, Y in a light cell: usable, N in a dark cell: unusable \label{tab:power}}
\begin{tblr}{
  colspec={lXXXXX},
  vlines,
  hlines,
  cells={halign=c},
  column{1-2}={halign=l},
  vspan=even,
  cell{1}{2}={halign=c,bg=gray,fg=white},
  cell{2}{1}={bg=gray,fg=white},
  cell{3}{5-6}={bg=lightgray,font=\bfseries},  
  cell{5}{4-6}={bg=lightgray,font=\bfseries},    
  cell{6}{3}={bg=lightgray,font=\bfseries},      
}
& \SetCell[c=5]{} Type of Distribution & & & &\\ 
\SetCell[r=5]{} \rotatebox{90}{\parbox{3.5cm}{\centering Type of Transformation}} & & Lognormal & Exponential & Gamma & Weibull \\
& Box-Cox & Y & Y & Y & Y \\ 
& Exponential & Y & Y & Y & Y\\
& Simple power & Y & Y & Y & Y \\
& Logarithmic & Y & Y & N & N \\ 
\end{tblr}
\end{table}

Answer 1

The extra height comes from the \parbox. If you reduce the width of the \parbox a bit, the rows become less tall.

If you need the rows to be even narrower, you can change the rowsep (but you'll have to ditch the idea of rotated text then).

\documentclass[11pt]{article}

\usepackage{tabularray}
\usepackage{geometry}
\usepackage{xcolor}
\usepackage{graphicx}

\begin{document}
    
\begin{table}[h!]
\centering
\caption[Transformation table]{Transformations generated by Mach et al. Y in a dark cell: highly recommended, Y in a light cell: usable, N in a dark cell: unusable \label{tab:power}}
\begin{tblr}{
  colspec={lXXXXX},
  vlines,
  hlines,
  cells={halign=c},
  column{1-2}={halign=l},
  vspan=even,
  cell{1}{2}={halign=c,bg=gray,fg=white},
  cell{2}{1}={bg=gray,fg=white},
  cell{3}{5-6}={bg=lightgray,font=\bfseries},  
  cell{5}{4-6}={bg=lightgray,font=\bfseries},    
  cell{6}{3}={bg=lightgray,font=\bfseries},      
%  rowsep = 0mm
}
& \SetCell[c=5]{} Type of Distribution & & & &\\ 
\SetCell[r=5]{} \rotatebox{90}{\parbox{2.6cm}{\centering Type of Transformation}} & & Lognormal & Exponential & Gamma & Weibull \\
& Box-Cox & Y & Y & Y & Y \\ 
& Exponential & Y & Y & Y & Y\\
& Simple power & Y & Y & Y & Y \\
& Logarithmic & Y & Y & N & N \\ 
\end{tblr}
\end{table}
    
\end{document}