\begin{table}
\centering
\begin{tblr}[         %% tabularray outer open
]                     %% tabularray outer close
{                     %% tabularray inner open
colspec={Q[]Q[]Q[]},
hline{2}={1-3}{solid, black, 0.05em},
hline{1}={1-3}{solid, black, 0.1em},
hline{4}={1-3}{solid, black, 0.1em},
}                     %% tabularray inner close
blah\_blah\_underscore & dollar.sign & percent.sign \\
1 & 3 & 5 \\
2 & 4 & 6 \\
\end{tblr}
\end{table} 
