\begin{table}
\centering
\begin{tblr}[         %% tabularray outer open
]                     %% tabularray outer close
{                     %% tabularray inner open
colspec={Q[]Q[]Q[]Q[]Q[]Q[]Q[]Q[]Q[]Q[]Q[]Q[]},
column{1}={}{halign=l,},
column{2,3,4,5,6,7,8,9,10,11,12}={}{halign=r,},
}                     %% tabularray inner close
\toprule
& under\_score & oh\&yeah<sup>2</sup> & disp & hp & drat & wt & qsec & vs & am & gear & carb \\ \midrule %% TinyTableHeader
under\_score & 1 & . & . & . & . & . & . & . & . & . & . \\
oh\&yeah<sup>2</sup> & \num{-.85} & 1 & . & . & . & . & . & . & . & . & . \\
disp & \num{-.85} & \num{.90} & 1 & . & . & . & . & . & . & . & . \\
hp & \num{-.78} & \num{.83} & \num{.79} & 1 & . & . & . & . & . & . & . \\
drat & \num{.68} & \num{-.70} & \num{-.71} & \num{-.45} & 1 & . & . & . & . & . & . \\
wt & \num{-.87} & \num{.78} & \num{.89} & \num{.66} & \num{-.71} & 1 & . & . & . & . & . \\
qsec & \num{.42} & \num{-.59} & \num{-.43} & \num{-.71} & \num{.09} & \num{-.17} & 1 & . & . & . & . \\
vs & \num{.66} & \num{-.81} & \num{-.71} & \num{-.72} & \num{.44} & \num{-.55} & \num{.74} & 1 & . & . & . \\
am & \num{.60} & \num{-.52} & \num{-.59} & \num{-.24} & \num{.71} & \num{-.69} & \num{-.23} & \num{.17} & 1 & . & . \\
gear & \num{.48} & \num{-.49} & \num{-.56} & \num{-.13} & \num{.70} & \num{-.58} & \num{-.21} & \num{.21} & \num{.79} & 1 & . \\
carb & \num{-.55} & \num{.53} & \num{.39} & \num{.75} & \num{-.09} & \num{.43} & \num{-.66} & \num{-.57} & \num{.06} & \num{.27} & 1 \\
\bottomrule
\end{tblr}
\end{table} 
