The LaTeX code below produces the pdf in the image which exceeds the line margin. The warning I’m getting is Overfull hbox (16.9449pt too wide) in paragraph at lines 39--51.

I’ve been trying to shrink the table slightly so that it fits within the margin and that final column is not distorted but I haven’t been successful. Any help will be appreciated!

begin{table}[h!]
    centering
    begin{minipage}{0.3textwidth}
        centering
        begin{tabular}{l|ll}
        toprule
         & multicolumn{2}{c}{Shift}  \
        Thr. & Label & None \
        midrule
        4.0 & textbf{0.576} & 0.660\
        4.5 & 0.565          & 0.656 \
        5.0* & 0.565         & 0.656    \
        5.5 & 0.570          & 0.660 \
        6.0 & 0.557          a& textbf{0.665} \
        bottomrule
        end{tabular}
        caption{Tab 1}
    end{minipage}
    hfill
    begin{minipage}{0.3textwidth}
        centering
        begin{tabular}{l|ll}
        toprule
        & multicolumn{2}{c}{Shift}  \
        Thr. & Label & None \
        midrule
        0.8  & textbf{0.536} & 0.622 \
        0.85 & 0.513          & 0.637 \
        0.9* & 0.514          & 0.639 \
        0.95 & 0.515          & 0.639\
        1.0    & 0.514        & textbf{0.641} \
        bottomrule
        end{tabular}
        caption{Tab 2}
    end{minipage}
    hfill
    begin{minipage}{0.3textwidth}
        centering
       begin{tabular}{l|ll}
        toprule
        & multicolumn{2}{c}{Shift}  \
        Thr. & Label None \
        midrule
        0.4  & 0.585           & 0.658 \
        0.45 & textbf{0.594}  & 0.644 \
        0.5*  & 0.584          & 0.657\
        0.55 & 0.590           & textbf{0.665} \
        0.6 & 0.589            & 0.643 \
        bottomrule
        end{tabular}
        caption{Tab3}
    end{minipage}
    caption{Test.}
    label{tab}
end{table}