documentclass[11pt,a4paper,titlepage]{article}
usepackage{booktabs}
usepackage[allow-number-unit-breaks]{siunitx}
begin{document}
begin{table}[!htbp]
centering
caption{Percentage of Correct Predictions and AUC Values by Kernel}
label{tab34}
begin{tabular*}{linewidth}{@{extracolsep{fill}}llSS}
toprule textbf{Model} & textbf{Kernel} & textbf{% Correct Classification} & textbf{AUC Values}\
midrule
Model 20 & Linear & 49.9 & 0.50\
Model 21 & Polynomial ($d = 2$) & 93.6 & 0.98 \
Model 22 & Radial & 49.9 & 0.50 \
bottomrule
end{tabular*}
end{table}
end{document}