EDITED: Add the requested horizontal rule.
EDITED: Added the blank line to get a new paragraph.
EDITED: Column justification.
Here is an edit that compiles. However, what is your question?
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[letterpaper, top=1in, bottom=1in, left=0.75in, right=0.75in]{geometry}
\usepackage{multirow,array,varwidth,spreadtab,}
\usepackage{siunitx,booktabs,caption}
\usepackage{ragged2e}
\newcolumntype{L}[1]{>{\RaggedRight\hspace{0pt}}p{#1}}
\newcolumntype{R}[1]{>{\RaggedLeft\hspace{0pt}}p{#1}}
\begin{document}
\captionsetup{labelformat=empty}
\begin{table}
\centering
\caption{DISCOUNTED \\ FUTURE NET INCOME -M\$ \\COMPOUNDED MONTHLY}
\vspace{-1em}\rule{0.3\textwidth}{1.25pt}
\begin{tabular}{cr}
0.00 = & 0 \\
0.00 = & 0\\
0.00 = & 0\\
0.00 = & 0\\
0.00 = & 0\\
\multicolumn{2}{l}{%
\footnotesize
%
}
\end{tabular}
\end{table}
Here is an alternative using \textit{ragged2e} and \textit{array}.
\begin{table}
\centering
\caption{DISCOUNTED \\ FUTURE NET INCOME -M\$ \\COMPOUNDED MONTHLY}
\vspace{-1em}\rule{0.3\textwidth}{1.25pt}
\begin{tabular}{L{.12\textwidth}R{.12\textwidth}}% From http://tex.stackexchange.com/questions/7347/fixed-column-width-table-with-text-left-aligned-in-cells
0.00 = & 0 \\
0.00 = & 0\\
0.00 = & 0\\
0.00 = & 0\\
0.00 = & 0\\
\multicolumn{2}{l}{%
\footnotesize
%
}
\end{tabular}
\end{table}
\end{document}

\documentclassand ends with\end{document}And then just the minimum information to show the problem or question. – R. Schumacher May 15 '15 at 03:27