begintableHbegintabularccchlinemultirow2波长 & multicolumn2c红 cline2-3 & multicolumn

要使表格变小，可以通过调整表格的宽度和字体大小来实现。以下是修改后的代码：

\begin{table}[H] \small % 调整字体大小为small \centering % 居中显示表格 \setlength{\tabcolsep}{4pt} % 调整列间距 \begin{tabular}{|c|cc|} \hline \multirow{2}{*}{波长} & \multicolumn{2}{c|}{红} \ \cline{2-3} & \multicolumn{1}{c|}{函数关系式} & 拟合系数 \ \hline 400nm & \multicolumn{1}{c|}{y = -0.031177 * x\textasciicircum{}2 + 0.861615 * x + 0.583776} & (-0.031177 , 0.861615 , 0.583776) \ \hline 420nm & \multicolumn{1}{c|}{y = -0.022021 * x\textasciicircum{}2 + 0.771411 * x + 0.227623} & (-0.022021 , 0.771411 , 0.227623) \ \hline 440nm & \multicolumn{1}{c|}{y = -0.022021 * x\textasciicircum{}2 + 0.742911 * x + 0.108269} & (-0.022021 , 0.742911 , 0.108269) \ \hline ...... & \multicolumn{1}{c|}{......} & ...... \ \hline 700nm & \multicolumn{1}{c|}{y = -0.000132 * x\textasciicircum{}2 + 0.001302 * x + 0.006047} & (-0.000132 , 0.001302 , 0.006047) \ \hline \end{tabular} \end{table}

通过设置字体大小为small，表格变小。通过设置列间距为4pt，可以使得表格更加紧凑