Examples:
\begin{enumerate}
\item
\begin{tabular}{ l c r }
1 & 2 & 3 \\
4 & 5 & 6 \\
7 & 8 & 9 \\
\end{tabular}
\item
\begin{tabular}{ l | c | r }
1 & 2 & 3 \\
4 & 5 & 6 \\
7 & 8 & 9 \\
\end{tabular}
\item
\begin{tabular}{ l | c | r }
\hline
1 & 2 & 3 \\
4 & 5 & 6 \\
7 & 8 & 9 \\
\hline
\end{tabular}
\item
\begin{tabular}{ l | c | r }
\hline
1 & 2 & 3 \\ \hline
4 & 5 & 6 \\ \hline
7 & 8 & 9 \\
\hline
\end{tabular}
\item
\begin{tabular}{ | l | c | r }
\hline
1 & 2 & 3 \\ \hline
4 & 5 & 6 \\ \hline
7 & 8 & 9 \\
\hline
\end{tabular}
\item
\begin{tabular}{ l *{6}{c} r }
\textbf{Team} & P & W & D & L & F & A & Pts \\
\hline
Manchester United & 6 & 4 & 0 & 2 & 10 & 5 & 12 \\
Celtic & 6 & 3 & 0 & 3 & 8 & 9 & 9 \\
Benfica & 6 & 2 & 1 & 3 & 7 & 8 & 7 \\
FC Copenhagen & 6 & 2 & 1 & 3 & 5 & 8 & 7 \\
\end{tabular}
\item
\begin{tabular}{ l *{6}{c} r }
\textbf{\color[HTML]{ff0000} Team } & \textbf{P} & \textbf{W} & \textbf{D} & \textbf{L} & \textbf{F} & \textbf{A} & \textbf{Pts} \\
\hline
Manchester United & 6 & 4 & 0 & 2 & 10 & 5 & 12 \\
Celtic \cite{einstein} & 6 & 3 & 0 & 3 & 8 & 9 & 9 \\
Benfica & 6 & 2 & 1 & 3 & 7 & 8 & 7 \\
FC Copenhagen & 6 & 2 & 1 & 3 & 5 & 8 & 7 \\
\end{tabular}
\end{enumerate}
Results:
References:
[1] https://en.wikibooks.org/wiki/LaTeX/Tables