Set padding for cells of a specific row (not all cells) and set vertical center alignment

Question

The context

I'm trying to create a table that meets the following conditions

1. the padding on all cells from the first row must be bigger than the default padding.
2. the content of all cells must be vertically center aligned.

Regarding the condition no. 1: I know how to change the padding on all cells but don't know how to do it for all cells of an specific row without causing this effect on all the other rows (see document below)

\documentclass{article}

\begin{document}

\def\arraystretch{2}

\noindent
\begin{tabular}{|c|c|c|}
   \hline a & b & c
\\ \hline a & b & c
\\ \hline a & b & c
\\ \hline
\end{tabular}

\end{document}

Regarding the condition no. 2: I know how to do it.

\documentclass{article}

\usepackage{array, lipsum}

\begin{document}

\noindent
\begin{tabular}{|m{5cm}|m{5cm}|}
   \hline a & \lipsum[1][1-2]
\\ \hline \lipsum[2][1-2] & b
\\ \hline
\end{tabular}

\end{document}

The question

How can I create a table that meet condition no. 1 and condition no. 2?

Answer 1

I use zero width rules piped into a zero width m-column to set the height of the rows. In addition, I define a new column type, M, which vertically and horizontally centres its content.

In example 2, I have defined a new command \rl, which allows you to set the row height individually.

Example 1 - same height rows

\documentclass{article}

\usepackage{array}
\newcolumntype{M}{>{\centering\arraybackslash}m{15pt}}

\begin{document}

\noindent
\begin{tabular}{|*{3}{M|}>{\rule{0pt}{30pt}}m{0pt}}
   \cline{1-3} a & b & j &
\\ \cline{1-3}  a & b & j &
\\ \cline{1-3}  a & b & j &
\\ \cline{1-3} 
\end{tabular}

\end{document}

Example 2 - different height rows

\documentclass{article}

\usepackage{array}
\newcolumntype{M}{>{\centering\arraybackslash}m{15pt}}
\newcommand{\rl}[1]{\rule{0pt}{#1pt}}


\begin{document}


\noindent
\begin{tabular}{|*{3}{M|}m{0pt}}
   \cline{1-3} a & b & j & \rl{16}
\\ \cline{1-3}  a & b & j &
\\ \cline{1-3}  a & b & j &\rl{30}
\\ \cline{1-3} 
\end{tabular}

\end{document}

Answer 2

In the environment {NiceTabular} of nicematrix, you have two keys cell-space-top-limit and cell-space-bottom-limit and a key cell-space-limits for their conjonction.

With the latest version of nicematrix (v. 5.18 of 2021-07-15), it's possible to fix the value of those parameters for a single row with the command \RowStyle.

\documentclass{article}
\usepackage{nicematrix}

\begin{document}

\newcolumntype{M}{>{\raggedright\arraybackslash}m{2.2cm}}

\begin{NiceTabular}{MMM}[hvlines,cell-space-limits=1mm]
some text & here also some text & text, text, text and text \\
some text & here also some text & text, text, text and text \\
\RowStyle[cell-space-limits=0pt]{}
some text & here also some text & text, text, text and text \\
some text & here also some text & text, text, text and text \\
\end{NiceTabular}

\end{document}

The package nicematrix also provides a key hvlines which draw all the rules.

Answer 3

I wouldn't use arraystretch to have vertically centered cells contents, as it asymmetrically expands the height and depth of cells. A better way uses package cellspace, which defines a minimal vertical padding at the top and bottom of cells in columns with specifier prefixed with the letter S (or C if you load siunitx).

Here is demo, with \cellspacetop-bottomlimit chosen so that the solution with arraystretch and the solution with cellspace result in tables of the same height:

\documentclass{article}
\usepackage{cellspace}
\setlength{\cellspacetoplimit}{8.5pt}
\setlength{\cellspacebottomlimit}{8.5pt}

\begin{document}

{\def\arraystretch{2}

\noindent
\begin{tabular}{|c|c|c|}
   \hline a & b & c
\\ \hline a & b & c
\\ \hline a & b & c
\\ \hline
\end{tabular}}
\qquad
\begin{tabular}{|Sc|Sc|Sc|}
   \hline a & b & c
\\ \hline a & b & c
\\ \hline a & b & c
\\ \hline
\end{tabular}

\end{document} 

Answer 4

Both conditions are met with this approach

\documentclass{article}

\usepackage{tabu, stackengine}

\usepackage{lipsum}

\begin{document}

\begin{tabu}{|m{80pt}|m{80pt}|m{80pt}|}
\hline

\addstackgap[80pt]{a}
& b
& \lipsum[1][1-2]
\\ \hline

A
& B
& C
\\ \hline

\end{tabu}

\end{document}