I assume you're using latex with autogenerated glossary, if not you probably should.
\usepackage[acronym]{glossaries}
\makeglossaries
\newacronym{MDBs}{MDBs}{Multilateral Development Banks}
If this is some acronym you will use more later, it's better to introduce it in the main text before it shows up in a table:
In this part of research we used \gls{MDBs}, the best stuff since slice bread, see \autoref{tab:table1}.
\begin{table}[h]
some stuff about \gls{MDBs}
\label{tab:table1}
\end{table}
If it is only used in this table and nowhere else there is little reason to make an acronym at all. Just spell it all out:
\begin{table}[h]
some stuff about Multilateral Development Banks.
\label{tab:table1}
\end{table}
If you really need or want to introduce the acronym in the table, it makes more sense to expand it in the caption. I don't remember how to do it in tex macro:
\begin{table}[h]
some stuff about Multilateral Development Banks^{1}.
\caption[Table about stuff]{This table contains stuff. Acronyms: \gls{MDBs}, \gls{ABC}, ...}
\label{tab:table1}
\end{table}