You have to compile at least twice with every change in the percentage (last) column (since it uses eqparbox
for getting the appropriate alignment).

\documentclass{book}
\usepackage[
margin=1in,
landscape
]{geometry} % Just for this example
\usepackage{booktabs,collcell,eqparbox,makecell}
\begin{document}
\begin{table}
\centering
\newcommand{\pa}[1]{\eqmakebox[CFNetvsNeuMF][r]{#1}}% Percentage alignment
\newcommand{\hlc}{\textbf}% Highlight cell
\caption{Comparison results of different methods in terms of NDCG@10 and HR@10.}
\begin{tabular}{ *{9}{c} >{\collectcell\pa}c<{\endcollectcell} }
\toprule
&
&
\multicolumn{4}{c}{Existing methods} &
\multicolumn{3}{c}{CFNet} &
\\
\cmidrule(lr){3-6}\cmidrule(lr){7-9}
Dataset & % \raisebox{.7\normalbaselineskip}[0pt][0pt]{Dataset}
Measures & % \raisebox{.7\normalbaselineskip}[0pt][0pt]{Measures}
ItemPop & eALS & DMF & NeuMF &
CFNet-rl & CFNet-ml & CFNet &
\multicolumn{1}{c}{\smash{\makecell[b]{Improvement of \\ CFNet \emph{vs.} NeuMF}}} \\
\midrule
ml-1m & HR & 0.4535 & 0.7018 & 0.6565 & \hlc{0.7210} &
0.7127 & 0.7073 & \hlc{0.7253} &
0.6\% \\
& NDCG & 0.2542 & 0.4280 & 0.3761 & \hlc{0.4387} &
0.4336 & 0.4264 & \hlc{0.4416} &
0.7\% \\
\addlinespace
lastfm & HR & 0.6628 & 0.8265 & 0.8840 & \hlc{0.8868} &
0.8840 & 0.8834 & \hlc{0.8995} &
1.4\% \\
& NDCG & 0.3862 & 0.5162 & 0.5804 & \hlc{0.6007} &
0.6001 & 0.5919 & \hlc{0.6186} &
3.0\% \\
\addlinespace
AMusic & HR & 0.2483 & 0.3711 & 0.3744 & 0.3891 &
0.3947 & \hlc{0.4071} & \hlc{0.4116} &
5.8\% \\
& NDCG & 0.1304 & 0.2352 & 0.2149 & 0.2391 &
\hlc{0.2504} & 0.2420 & \hlc{0.2601} &
8.8\% \\
\addlinespace
AToy & HR & 0.2840 & 0.3717 & 0.3535 & 0.3650 &
0.3746 & \hlc{0.3931} & \hlc{0.4150} &
13.7\% \\
& NDCG & 0.1518 & \hlc{0.2434} & 0.2016 & 0.2155 &
0.2271 & 0.2293 & \hlc{0.2513} &
16.6\% \\
\bottomrule
\end{tabular}
\end{table}
\end{document}
\documentclass{}...\begin{document}
etc. As it is, most of our users will be very reluctant to touch your question, and you are left to the mercy of our procrastination team who are very few in number and very picky about selecting questions. You can improve your question by adding a minimal working example (MWE) that more users can copy/paste onto their systems to work on. If no hero takes the challenge we might have to close your question. – Stefan Pinnow Oct 8 at 16:40booktabs
package. – barbara beeton Oct 8 at 17:40