In table, how to hide borders and merge different cells?

Question

Trying to convert this table 1 to the table 2 format,

Table 2 (single table), merging the cells 1x1 & 1x2, merging the entire 3rd column and hiding the borders, and again merging the 1x4 & 1x5, with defined column width and row height.

Any ideas or suggestions apart from this method are also welcome

\documentclass{article}
\begin{document}
\begin{center}
\begin{tabular}{|l|l|l|l|l|}
\hline & Column A & & & Column B \\
\hline i & Wind & & a & Monsoon \\
\hline ii & Anemometer & & b & Cyclone \\
\hline iii & Hurricane, Typhoon & & c & Measures speed of Wind \\
\hline iv & Mausam & & d & Moving air \\
\hline
\end{tabular}
\end{center}
\end{document}

Answer 1

Slightly different from user187803's answer with the third column merged (though it makes no difference).

EDIT

• Thanks to NBur, I removed unnecessary packages;
• Now the column width and arraystretch can be set. The width of column is set by the value after p. The height of the table should be automatically set as you see the word wrap is on. But you can also set the arraystretch freely here.

\documentclass{article}
\usepackage{multirow,multirow}

\begin{document}
\begin{table}[htbp]
  \centering
  \caption{Add caption}
  \bgroup
    \renewcommand{\arraystretch}{1.2}% <-- array stretch for the table
    \begin{tabular}{|p{1cm}|p{3.5cm}|p{2cm}|p{1cm}|p{3.5cm}|}
      \cline{1-2}\cline{4-5} \multicolumn{2}{|c|}{\textbf{Column A}} & \multirow{5}[10]{*}{} &   \multicolumn{2}{c|}{\textbf{Column B}} \\
      \cline{1-2}\cline{4-5} i & Wind &   & a & Monsoon \\
      \cline{1-2}\cline{4-5} ii & Anemometer &   & b & Cyclone \\
      \cline{1-2}\cline{4-5} iii & Hurricane, Typhoon &   & c & Measures speed of Wind \\
      \cline{1-2}\cline{4-5} iv & Mausam, longer and longer and longer &   & d & Moving air \\
      \cline{1-2}\cline{4-5}
    \end{tabular}%
  \egroup
  \label{tab:addlabel}%
\end{table}%

\end{document}

Actually I made this table using Excel2LaTeX which is rather convenient.

Answer 2

You can use \cline and \multicolumn.
EDIT
For defined column widths, you can use p{width} in the column definition.
For defined row heights, you can redefine \arraystretch.

\documentclass{article}
\begin{document}
\begin{center}
    \sffamily
    \def\arraystretch{1.5}
    \begin{tabular}{|l|p{3.5cm}|p{2cm}|l|l|}
        \cline{1-2}\cline{4-5} \multicolumn{2}{|c|}{\textbf{Column A}} & & \multicolumn{2}{|c|}{\textbf{Column B}} \\
        \cline{1-2}\cline{4-5} i & Wind & & a & Monsoon \\
        \cline{1-2}\cline{4-5} ii & Anemometer & & b & Cyclone \\
        \cline{1-2}\cline{4-5} iii & Hurricane, Typhoon & & c & Measures speed of Wind \\
        \cline{1-2}\cline{4-5} iv & Mausam & & d & Moving air \\
        \cline{1-2}\cline{4-5}
    \end{tabular}
\end{center}
\end{document}

Answer 3

With relatively new and versatile tabularray package the table code is short and simple:

\documentclass{article}
\usepackage{tabularray}

\begin{document}
    \begin{center}
\begin{tblr}{hline{1-Z}={1-2, 4-5}{solid}, vlines,
             colspec = {Q[l,6mm] X[l] Q[l,12mm] Q[l,6mm] X[l]},
             row{1} = {font=\bfseries, c}
             }
\SetCell[c=2]{c}    Column A 
    &               &   &   \SetCell[c=2]{c}    Column B 
                            &                           \\
i   & Wind          &   & a & Monsoon                   \\
ii  & Anemometer    &   & b & Cyclone                   \\
iii & Hurricane, Typhoon 
                    &   & c & Measures speed of Wind    \\
iv  & Mausam        &   & d & Moving air                \\
\end{tblr}
    \end{center}
\end{document}

Answer 4

With {NiceTabular} of nicematrix.

\documentclass{article}
\usepackage{nicematrix}

\begin{document}
\begin{center}
\begin{NiceTabular}{ccccc}
\RowStyle[bold]{}
\Block[hvlines]{*-2}{}
\Block{1-2}{Column A}
    &               &   & \Block[hvlines]{*-2}{}  
                          \Block{1-2}{Column B}       \\
i   & Wind          &   & a & Monsoon                 \\
ii  & Anemometer    &   & b & Cyclone                 \\
iii & Hurricane, Typhoon 
                    &   & c & Measures speed of Wind  \\
iv  & Mausam        &   & d & Moving air              \\
\end{NiceTabular}
\end{center}
\end{document}

You need several compilations (because nicematrix uses PGF/Tikz nodes under the hood).