Enumerate over two columns in tabular environment

One way to do it would be to use a custom counter. Below I have adapted the solution from a very similar question Making the table enumerated, which yields:

Notes:

• I have used a \newcolumntype from the array package to define a P column type to simplify the use of the tabular environments in adding the labels:

    \newcolumntype{P}[1]{>{\AddLabel}p{#1}<{}}
  

  When a column of type P{} is used, the \AddLabel macro is invoked first, which increments the counter and automatically adds the counters value as a label before using the regular p{} column type.

• \makebox is used to ensure that the labels are aligned to the right within a space equal to the width that would be required to typeset 99 (assuming that your max will be two digits.

• When using the \multicolumn, you need to manually include \AddLabel to generate the label as needed.

• At the start of any subsequent tables that use the P column type as defined here, one needs to reset the counter via \setcounter{Label}{0}. Otherwise a table following the one in this example would start the numbering from 12.

  If you are using this table numerous times in your document, the I would suggest either defining a custom environment, or perhaps redefining the \begin{tabular} environment to automatically reset this counter. See How can I center all tables in a document? for help with this if desired.

Code:

\documentclass{article}
\usepackage{array}%            \newcolumntype
\usepackage{calc}%             \widthof

\newcounter{Label}
\newcommand*{\AddLabel}{%
    \stepcounter{Label}%
    \makebox[\widthof{99}][r]{\arabic{Label}}.~%
}%

\newcolumntype{P}[1]{>{\AddLabel}p{#1}<{}}

\begin{document}
\setcounter{Label}{0}% Start at beginning (Really only needed for subsequent uses)
\begin{tabular}{|P{5cm}P{5cm}|}
\hline
\multicolumn{2}{|l|}{Testing Modifications (highlight or circle)} \\
\hline
Time Limit Waved         & On-Task Focusing Prompts \\
Exam/Sep Location        & Waive Spelling Reqs \\
Questions Read Aloud     & Revise Test Format \\
Answers Any Way          & Revise Test Directions \\
Calc/Abacus Permitted    & Breaks \\
\multicolumn{2}{|c|}{\AddLabel Other: \underline{\hspace{10cm}}} \\
\hline
\end{tabular}
\end{document}

Maybe you do not need a complicated tabular environment for this.

Edit: As requested in the aklingensmith's comment, the title and font background could be set easily with \fcolorbox and color or xcolor packages. Other good option is the mdframed package because their versatility (Note that with this package is not needed call to color packages directly), but also is possible do a fancy box without it.

\documentclass{article}
\usepackage[framemethod=TikZ]{mdframed}
\usepackage{fancybox}
\mdfdefinestyle{MyFrame}{%
    linecolor=black!50,
    outerlinewidth=0.1em,
    skipabove=.5\baselineskip,
    skipbelow=.5\baselineskip,
    roundcorner=1em,
    leftmargin=.045\textwidth,
    rightmargin=.1\textwidth,
    innertopmargin=1ex,
    innerbottommargin=.5\baselineskip,
    innerrightmargin=1em,
    innerleftmargin=1em,
    backgroundcolor=yellow!05!white,
    frametitlerule=true,
    frametitlerulecolor=black!40!yellow!90,
    frametitlebackgroundcolor=black!85,
    frametitlerulewidth=0.2em}


\usepackage{multicol}
\begin{document}

\fbox{
\begin{minipage}{0.8\textwidth}
Testing Modifications (highlight or circle) \hrule
\begin{enumerate}
  \setlength{\itemsep}{0pt}
  \setlength{\parskip}{0pt}
\begin{multicols}{2}
    \item Time Limit Waved
    \item Exam/Sep Location
    \item Questions Read Aloud
    \item Answers Any Way
    \item Calc/Abacus Permitted
    \item On-Task Focusing Prompts
    \item Waive Spelling Reqs
    \item Revise Test Format 
    \item Revise Test Directions 
    \item Breaks 
\end{multicols}
    \item Other: \dotfill 
\end{enumerate}
\smallskip
\end{minipage}
}   

\smallskip

{\color{blue} \Ovalbox{
\begin{minipage}{0.8\textwidth}
\centering\fcolorbox{blue!90}{blue!40!black!50}{\color{white}\bfseries ~~ Testing Modifications (highlight or circle) ~~ } \color{red!40!black}
\begin{enumerate}
  \setlength{\itemsep}{0pt}
  \setlength{\parskip}{0pt}
\begin{multicols}{2}
    \item Time Limit Waved
    \item Exam/Sep Location
    \item Questions Read Aloud
    \item Answers Any Way
    \item Calc/Abacus Permitted
    \item On-Task Focusing Prompts
    \item Waive Spelling Reqs
    \item Revise Test Format 
    \item Revise Test Directions 
    \item Breaks 
\end{multicols}
    \item Other: \dotfill 
\end{enumerate}
\smallskip
\end{minipage}
}   
}






\mdfsetup{frametitlealignment=\center}

\begin{mdframed}[style=MyFrame, frametitle={\color{white}Testing Modifications (highlight or circle)}]


\begin{enumerate}
  \setlength{\itemsep}{0pt}
  \setlength{\parskip}{0pt}
\begin{multicols}{2}
    \item Time Limit Waved
    \item Exam/Sep Location
    \item Questions Read Aloud
    \item Answers Any Way
    \item Calc/Abacus Permitted
    \item On-Task Focusing Prompts
    \item Waive Spelling Reqs
    \item Revise Test Format 
    \item Revise Test Directions 
    \item Breaks 
\end{multicols}
    \item Other: \dotfill 
\end{enumerate}
\smallskip

\end{mdframed}


\end{document}