
\documentclass[border=5pt,multi=true]{standalone}
\usepackage{standalone}
\usepackage{ifthen}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{upgreek}
\usepackage{xspace}
\usepackage{color}
\usepackage{amsmath}
\usepackage{graphicx}
\usepackage{bm}
\usepackage{ctable}
\usepackage{placeins}
\usepackage{grffile}
\usepackage{subfig}
\usepackage{mathrsfs}
\usepackage{multirow}
\usepackage{relsize}
\usepackage{afterpage}
\usepackage{lmodern}
\usepackage{mciteplus}
\usepackage{hyperref}
\usepackage{hypcap}
\usepackage{svg}
\usepackage{svg}

\begin{document}
  
    \small
    \begin{tabular}[t]{c|r|r|r|r|r}
      \toprule
      \multicolumn{1}{c|}{Stream}
      & \multicolumn{1}{c|}{ $\mathcal{A}$ \xspace} 
      & \multicolumn{1}{c|}{ $\mathcal{B}$ \xspace $[\%]$}
      & \multicolumn{1}{c|}{ $ {\varepsilon_{\mathrm{sel}\xspace}}$ \xspace}
      & \multicolumn{1}{c|}{$N_\mathrm{bkg}\xspace$}
      & \multicolumn{1}{c}{$N$} \\
      \midrule
       $\tau_\mu\tau_\mu$ \xspace & $0.405 \pm 0.006$ & $3.031 \pm 0.014$ & $0.138 \pm 0.006$ 
      & $ 41.6 \pm 8.5$ & $124$ \\
       $\tau_\mu\tau_e$ \xspace  & $0.248 \pm 0.004$ & $6.208 \pm 0.020$ & $0.517 \pm 0.012$
      & $129.7 \pm 4.9$ & $421$ \\
       $\tau_e\tau_\mu$ \xspace  & $0.152 \pm 0.002$ & $6.208 \pm 0.020$ & $0.344 \pm 0.016$
      & $ 56.6 \pm 3.3$ & $155$ \\
       $\tau_\mu\tau_ h\xspace$ \xspace  & $0.182 \pm 0.002$ & $16.933 \pm 0.056$ & $0.135 \pm 0.004$
      & $ 53.3 \pm 0.8$ & $189$ \\
       $\tau_e\tau_ h\xspace$ \xspace   & $0.180 \pm 0.002$ & $17.341 \pm 0.057$ & $0.082 \pm 0.004$
      & $ 36.6 \pm 0.9$ & $101$ \\
      \bottomrule
    \end{tabular}
  
\end{document}
