As percusse said in his comment, the most convenient way to go is to exploit the tikzmark macro (just one reference: Adding a large brace next to a body of text).
This solution allows to draw both braces and arrows through:
\drawbrace command;
\drawcurvedarrow command,
as well as to put some annotations via \annote and it exploits a variant of tikzmark macro in which it is possible to customize a bit the position of the marker via shifts.
Add a curved arrow and a bracket to a table
As percusse said in his comment, the most convenient way to go is to exploit the tikzmark macro (just one reference: Adding a large brace next to a body of text).
This solution allows to draw both braces and arrows through:
as well as to put some annotations via \annote and it exploits a variant of tikzmark macro in which it is possible to customize a bit the position of the marker via shifts.
The code:
\documentclass[border=20pt,png]{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.pathreplacing,calc}
\newcommand{\tikzmark}[2][-3pt]{\tikz[remember picture, overlay, baseline=-0.5ex]\node#1{};}
\tikzset{brace/.style={decorate, decoration={brace}},
brace mirrored/.style={decorate, decoration={brace,mirror}},
}
\newcounter{brace}
\setcounter{brace}{0}
\newcommand{\drawbrace}[3][brace]{%
\refstepcounter{brace}
\tikz[remember picture, overlay]\draw[#1] (#2.center)--(#3.center)node[pos=0.5, name=brace-\thebrace]{};
}
\newcounter{arrow}
\setcounter{arrow}{0}
\newcommand{\drawcurvedarrow}[3][]{%
\refstepcounter{arrow}
\tikz[remember picture, overlay]\draw (#2.center)edge[#1]node[coordinate,pos=0.5, name=arrow-\thearrow]{}(#3.center);
}
% #1 options, #2 position, #3 text
\newcommand{\annote}[3][]{%
\tikz[remember picture, overlay]\node[#1] at (#2) {#3};
}
\begin{document}
\begin{tabular}{ | l | l |}
\hline
letter & number \ \hline
\tikzmark[xshift=-8pt,yshift=1ex]{x}A & 1\tikzmark[xshift=3.5em]{a} \ \hline
A & 2 \ \hline
\tikzmark[xshift=-8pt,yshift=-1ex]{y}A & 1\tikzmark[xshift=3.5em]{b} \ \hline
\tikzmark[xshift=-8pt,yshift=1ex]{w}B & 1 \ \hline
\tikzmark[xshift=-8pt,yshift=-1ex]{z}B & 2 \ \hline
\end{tabular}
\drawcurvedarrow[bend left=60,-stealth]{a}{b}
\drawbrace[brace mirrored, thick]{x}{y}
\drawbrace[brace mirrored, thick]{w}{z}
\annote[right]{arrow-1}{Duplicate}
\annote[left]{brace-1}{A}
\annote[left]{brace-2}{B}
\end{document}
http://tex.stackexchange.com/questions/117873/add-a-curved-arrow-and-a-bracket-to-a-table