Simple table with caption:

\begin{longtable}[]{@{}rlcl@{}}
\caption{Demonstration of simple table syntax.}\tabularnewline
\toprule
Right & Left & Center & Default\tabularnewline
\midrule
\endfirsthead
\toprule
Right & Left & Center & Default\tabularnewline
\midrule
\endhead
12 & 12 & 12 & 12\tabularnewline
123 & 123 & 123 & 123\tabularnewline
1 & 1 & 1 & 1\tabularnewline
\bottomrule
\end{longtable}

Simple table without caption:

\begin{longtable}[]{@{}rlcl@{}}
\toprule
Right & Left & Center & Default\tabularnewline
\midrule
\endhead
12 & 12 & 12 & 12\tabularnewline
123 & 123 & 123 & 123\tabularnewline
1 & 1 & 1 & 1\tabularnewline
\bottomrule
\end{longtable}

Simple table indented two spaces:

\begin{longtable}[]{@{}rlcl@{}}
\caption{Demonstration of simple table syntax.}\tabularnewline
\toprule
Right & Left & Center & Default\tabularnewline
\midrule
\endfirsthead
\toprule
Right & Left & Center & Default\tabularnewline
\midrule
\endhead
12 & 12 & 12 & 12\tabularnewline
123 & 123 & 123 & 123\tabularnewline
1 & 1 & 1 & 1\tabularnewline
\bottomrule
\end{longtable}

Multiline table with caption:

\begin{longtable}[]{@{}clrl@{}}
\caption{Here's the caption. It may span multiple lines.}\tabularnewline
\toprule
\begin{minipage}[b]{0.13\columnwidth}\centering
Centered Header\strut
\end{minipage} & \begin{minipage}[b]{0.12\columnwidth}\raggedright
Left Aligned\strut
\end{minipage} & \begin{minipage}[b]{0.14\columnwidth}\raggedleft
Right Aligned\strut
\end{minipage} & \begin{minipage}[b]{0.30\columnwidth}\raggedright
Default aligned\strut
\end{minipage}\tabularnewline
\midrule
\endfirsthead
\toprule
\begin{minipage}[b]{0.13\columnwidth}\centering
Centered Header\strut
\end{minipage} & \begin{minipage}[b]{0.12\columnwidth}\raggedright
Left Aligned\strut
\end{minipage} & \begin{minipage}[b]{0.14\columnwidth}\raggedleft
Right Aligned\strut
\end{minipage} & \begin{minipage}[b]{0.30\columnwidth}\raggedright
Default aligned\strut
\end{minipage}\tabularnewline
\midrule
\endhead
\begin{minipage}[t]{0.13\columnwidth}\centering
First\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright
row\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedleft
12.0\strut
\end{minipage} & \begin{minipage}[t]{0.30\columnwidth}\raggedright
Example of a row that spans multiple lines.\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.13\columnwidth}\centering
Second\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright
row\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedleft
5.0\strut
\end{minipage} & \begin{minipage}[t]{0.30\columnwidth}\raggedright
Here's another one. Note the blank line between rows.\strut
\end{minipage}\tabularnewline
\bottomrule
\end{longtable}

Multiline table without caption:

\begin{longtable}[]{@{}clrl@{}}
\toprule
\begin{minipage}[b]{0.13\columnwidth}\centering
Centered Header\strut
\end{minipage} & \begin{minipage}[b]{0.12\columnwidth}\raggedright
Left Aligned\strut
\end{minipage} & \begin{minipage}[b]{0.14\columnwidth}\raggedleft
Right Aligned\strut
\end{minipage} & \begin{minipage}[b]{0.30\columnwidth}\raggedright
Default aligned\strut
\end{minipage}\tabularnewline
\midrule
\endhead
\begin{minipage}[t]{0.13\columnwidth}\centering
First\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright
row\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedleft
12.0\strut
\end{minipage} & \begin{minipage}[t]{0.30\columnwidth}\raggedright
Example of a row that spans multiple lines.\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.13\columnwidth}\centering
Second\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright
row\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedleft
5.0\strut
\end{minipage} & \begin{minipage}[t]{0.30\columnwidth}\raggedright
Here's another one. Note the blank line between rows.\strut
\end{minipage}\tabularnewline
\bottomrule
\end{longtable}

Table without column headers:

\begin{longtable}[]{@{}rlcr@{}}
\toprule
\endhead
12 & 12 & 12 & 12\tabularnewline
123 & 123 & 123 & 123\tabularnewline
1 & 1 & 1 & 1\tabularnewline
\bottomrule
\end{longtable}

Multiline table without column headers:

\begin{longtable}[]{@{}clrl@{}}
\toprule
\endhead
\begin{minipage}[t]{0.13\columnwidth}\centering
First\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright
row\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedleft
12.0\strut
\end{minipage} & \begin{minipage}[t]{0.30\columnwidth}\raggedright
Example of a row that spans multiple lines.\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.13\columnwidth}\centering
Second\strut
\end{minipage} & \begin{minipage}[t]{0.12\columnwidth}\raggedright
row\strut
\end{minipage} & \begin{minipage}[t]{0.14\columnwidth}\raggedleft
5.0\strut
\end{minipage} & \begin{minipage}[t]{0.30\columnwidth}\raggedright
Here's another one. Note the blank line between rows.\strut
\end{minipage}\tabularnewline
\bottomrule
\end{longtable}