Table goes right side instead of staying centered

Question

I just started using LateX, this table stays on the right no matter what. How can I center it by using the left space?

Answer 1

\documentclass{article}
\usepackage{siunitx,booktabs}
\sisetup{uncertainty-mode=separate}

\begin{document}
    \begin{table}
        \centering
        \begin{tabular}{cSS}
            \toprule
            {$N$} & {diametro (\unit{\mm})} & {$\cos\theta$ ($\qty[print-unity-mantissa = false]{e-6}{\radian}$)} \\\midrule
            7 & 48\pm1 & 99990\pm1\\
            6 & 63\pm1&99983\pm1\\
            5&74\pm1&99977\pm1\\
            4&88\pm1&99967\pm1\\
            3&95\pm1&99962\pm1\\
            2&103\pm1&99955\pm1\\
            1&109\pm1&99949\pm1\\\bottomrule
        \end{tabular}
        \caption{Caption}
        \label{tab:my_label}
    \end{table}
\end{document}

Answer 2

Without interchanges of columns and rows:

By use of tabularray table and enabled two line text in the first column:

\documentclass{article}
\usepackage{tabularray}
\UseTblrLibrary{siunitx}

\begin{document}
    \begin{table}
    \small
    \sisetup{uncertainty-mode = separate,
             tight-spacing}
\begin{tblr}{hline{1,2,Z},
             colspec = {@{} Q[c,m] *{7}{X[c, si={table-format=5.0(1)}]} @{}},
             colsep  = 3pt,
             row{1}  = {guard}
             }
$N$ & 7         &   6       &   5       &   4       &   3       &   2       &   1       \\ 
{diametro\\ (\unit{\mm})}
    & 48(1)     & 63(1)     & 74(1)     & 88(1)     & 95(1)     &103(1)     & 109(1)    \\
{$\cos\theta$\\ (\qty{e-6}{\radian})}
    & 99990(1)  & 99983(1)  & 99977(1)  & 99967(1)  & 99962(1)  & 99955(1)  & 99949(1)  \\
    \end{tblr}
\caption{Caption}
\label{tab:my_label}
    \end{table}
\end{document}