documentclass[12pt]{standalone}
usepackage{caption,booktabs,array}
UseRawInputEncoding
begin{document}
minipage{textwidth}
begin{tabular}{@{extracolsep{4pt}}>{hangindent=1.5emhangafter=1}p{2in}rrrrrrr}
toprule
{} & multicolumn{3}{c}{Treatment A} & multicolumn{3}{c}{Treatment B}  & {}\
cmidrule{2-4}
cmidrule{5-7}
 & Lorem & ipsum & dolor & sit & amets & consetetur & sadipscing \
  hline
luptatum blandit invidunt takimata & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 \
  sanctus eirmod sea labore & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 \
  erats sea eirmod blandit & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 \
  sea iriure illum eum & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 \
  zzril consetetur ipsum takimata & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 \
  dolore hendrerit justo sit & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 \
  sit augue et Lorem & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 \
  labore amets et dolores & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 \
  ipsum justo autem vel & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 \
  aliquyam velit luptatum Lorem & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 & 9.99 \
   hline
end{tabular}

captionof{table}{My caption}
endminipage
end{document}