I have the following LATEX document:
\documentclass[a4paper,12pt]{article}
\begin{document}
\section{Enemies}
\begin{table}[ht]
\begin{tabular}{c c c c c} % centered columns (4 columns)
First Name & Last Name & Phone & Address & Category \\ [0.5ex] % inserts table
%heading
\hline % inserts single horizontal line
Grey&Beard&1234567890&the ocean&Enemies\\
\hline %inserts single line
\end{tabular}
\end{table}
\section{Friends}
\begin{table}[ht]
\begin{tabular}{c c c c c} % centered columns (4 columns)
First Name & Last Name & Phone & Address & Category \\ [0.5ex] % inserts table
%heading
\hline % inserts single horizontal line
John&Doe&1234567890&1424 Brooklyn Ave.&Friends\\
\hline %inserts single line
\end{tabular}
\end{table}
\section{Relatives}
\begin{table}[ht]
\begin{tabular}{c c c c c} % centered columns (4 columns)
First Name & Last Name & Phone & Address & Category \\ [0.5ex] % inserts table
%heading
\hline % inserts single horizontal line
My&Self&1234567890&My current location&Relatives\\
\hline %inserts single line
\end{tabular}
\end{table}
\section{Mythical Beasts}
\begin{table}[ht]
\begin{tabular}{c c c c c} % centered columns (4 columns)
First Name & Last Name & Phone & Address & Category \\ [0.5ex] % inserts table
%heading
\hline % inserts single horizontal line
Puff&Dragon&1234567890&cave by the ocean&Mythical Beasts\\
\hline %inserts single line
\end{tabular}
\end{table}
\section{Public Figures}
\begin{table}[ht]
\begin{tabular}{c c c c c} % centered columns (4 columns)
First Name & Last Name & Phone & Address & Category \\ [0.5ex] % inserts table
%heading
\hline % inserts single horizontal line
Santa&Claus&10234987&North Pole&Public Figures\\
\hline %inserts single line
\end{tabular}
\end{table}
\end{document}
This is what it looks like after being compiled:

As you can see, the first few sections render properly, but after the first three the other sections' content appears outside of the sections. I tried reordering the sections and the same thing happens.
What is the problem?
EDIT:
New example:
\documentclass[a4paper,12pt]{article}
\title{Contact List}
\date{\today}
\begin{document}
\maketitle
\section{Enemies}
\begin{table}[!h] % note the !
\begin{tabular}{c c c c c} % centered columns (4 columns)
First Name & Last Name & Phone & Address & Category \\ [0.5ex] % inserts table
%heading
\hline % inserts single horizontal line
Grey&Beard&1234567890&the ocean&Enemies\\
Grey&Beard&1234567890&the ocean&Enemies\\
Grey&Beard&1234567890&the ocean&Enemies\\
Grey&Beard&1234567890&the ocean&Enemies\\
Grey&Beard&1234567890&the ocean&Enemies\\
\hline %inserts single line
\end{tabular}
\end{table}
\section{Friends}
\begin{table}[!h] % note the !
\begin{tabular}{c c c c c} % centered columns (4 columns)
First Name & Last Name & Phone & Address & Category \\ [0.5ex] % inserts table
%heading
\hline % inserts single horizontal line
John&Doe&1234567890&1424 Brooklyn Ave.&Friends\\
\hline %inserts single line
\end{tabular}
\end{table}
\section{Relatives}
\begin{table}[!h] % note the !
\begin{tabular}{c c c c c} % centered columns (4 columns)
First Name & Last Name & Phone & Address & Category \\ [0.5ex] % inserts table
%heading
\hline % inserts single horizontal line
My&Self&1234567890&My current location&Relatives\\
\hline %inserts single line
\end{tabular}
\end{table}
\section{Mythical Beasts}
\begin{table}[!h] % note the !
\begin{tabular}{c c c c c} % centered columns (4 columns)
First Name & Last Name & Phone & Address & Category \\ [0.5ex] % inserts table
%heading
\hline % inserts single horizontal line
Puff&Dragon&1234567890&cave by the ocean&Mythical Beasts\\
\hline %inserts single line
\end{tabular}
\end{table}
\section{Public Figures}
\begin{table}[!h] % note the !
\begin{tabular}{c c c c c} % centered columns (4 columns)
First Name & Last Name & Phone & Address & Category \\ [0.5ex] % inserts table
%heading
\hline % inserts single horizontal line
Santa&Claus&10234987&North Pole&Public Figures\\
\hline %inserts single line
\end{tabular}
\end{table}
\end{document}





!hdoesn't override all of them. For a more detailed explanation look at How to influence the position of float environments. – Jason Zentz Nov 23 '14 at 18:11floatpackage and the[H]declaration for your new MWE. – Jason Zentz Nov 23 '14 at 18:30