As barbara beeton already said, you can't wrap a float like table in a box and then scale it, your need to use its content only. However, you can redefine table to apply the scaling code automatically to its content as shown below.
Note that this non-optimal as you should scale text to much in LaTeX and the alignment of caption and actual table (the tabular) can be disturbed.
\documentclass{article}
\usepackage{lipsum}% for example text only
\usepackage{adjustbox}% for the scaling
\let\oldtable\table
\let\endoldtable\endtable
\renewenvironment{table}[1][]%
{\oldtable[#1]\adjustbox{varwidth=\linewidth,scale=3,center}\bgroup}
{\egroup\endoldtable}
\begin{document}
\lipsum% insert example text
\begin{table}[hp]
\centering
\caption{My table}\label{fig:figure1}
\begin{tabular}{lll}
a & b & c \\
a & b & c \\
\end{tabular}
\end{table}
\lipsum% insert example text
\end{document}
\tabcolsep. – Bernard Apr 04 '17 at 23:06tableenvironment is a float, it is not possible to wrap it in another environment for the purposes of scaling. that would have to be done inside the table environment. the only possible approach i can think of would be to redefine the table environment (to be used only temporarily) to create a wrapper that calls the "oldtable" with the scaling code inside of it. (i'm not competent enough to try to code that.) – barbara beeton Apr 05 '17 at 00:48