\begin{table}[htbp]
\centering
\caption{Add caption}
\begin{tabular}{|c|c|c|}
\hline
I (mA) & V (V) \pm 0.0001 & L12 (H) \bigstrut\\
\hline
1 & 0.3 & 1.5 \bigstrut\\
\hline
2 & 0.20 & 1.30 \bigstrut\\
\hline
3 & 1.29 & 1.5 \bigstrut\\
\hline
4 & 1.9 & 1.62 \bigstrut\\
\hline
5 & 2.51 & 1.68 \bigstrut\\
\hline
6 & 3.11 & 1.2 \bigstrut\\
\hline
7 & 3.6 & 1.4 \bigstrut\\
\hline
8 & 4.5 & 1.19 \bigstrut\\
\hline
9 & 5.0 & 1.1 \bigstrut\\
\hline
10 & 6.07 & 1.8 \bigstrut\\
\hline
\end{tabular}
\label{tab:addlabel}
\end{table}
решение1
Включитьbigstrut
упаковать и pm
изменить$\pm$
\documentclass[]{article}
\usepackage{bigstrut}
\begin{document}
\begin{table}[htbp]
\centering
\caption{Add caption}
\begin{tabular}{|c|c|c|}
\hline
I (mA) & V (V) $\pm$ 0.0001 & L12 (H) \bigstrut\\
\hline
1 & 0.3 & 1.5 \bigstrut\\
\hline
2 & 0.20 & 1.30 \bigstrut\\
\hline
3 & 1.29 & 1.5 \bigstrut\\
\hline
4 & 1.9 & 1.62 \bigstrut\\
\hline
5 & 2.51 & 1.68 \bigstrut\\
\hline
6 & 3.11 & 1.2 \bigstrut\\
\hline
7 & 3.6 & 1.4 \bigstrut\\
\hline
8 & 4.5 & 1.19 \bigstrut\\
\hline
9 & 5.0 & 1.1 \bigstrut\\
\hline
10 & 6.07 & 1.8 \bigstrut\\
\hline
\end{tabular}
\label{tab:addlabel}
\end{table}
\end{document}
решение2
Я бы переделал вашу таблицу следующим образом:
\documentclass{article}
\usepackage{booktabs} % added
\usepackage{siunitx} % added
\begin{document}
\begin{table}[htbp]
\centering
\caption{Add caption}
\label{tab:addlabel}
\renewcommand\arraystretch{1.1}% added
\begin{tabular}{ S[table-format=2.0]% changed to use S column type from siunitx
*{2}{S[table-format=1.2]}
}
\toprule % rules from booktabs
{I (mA)} & {V (V) $\pm$ 0.0001}
& {L12 (H)} \\
\midrule
1 & 0.3 & 1.5 \\
2 & 0.20 & 1.30 \\
3 & 1.29 & 1.5 \\
4 & 1.9 & 1.62 \\
5 & 2.51 & 1.68 \\
6 & 3.11 & 1.2 \\
7 & 3.6 & 1.4 \\
8 & 4.5 & 1.19 \\
9 & 5.0 & 1.1 \\
10 & 6.07 & 1.8 \\
\bottomrule
\end{tabular}
\end{table}
\end{document}