\usepackage{multirow}

\begin{table}
\begin{tabular}{lllccccc}
\hline
Object & $M_{\rm BH}$ & Instrument & Date & Exp. time & Seeing \\
\hline
 & ($10^3 M_{\odot}$) &  &  & (sec) & (arcsec)\\ 
\hline
\hline
J122732.18+075747.7 & 69 & MagE & 10/07/2017  & 3600 & 1.2\\
J171409.04+584906.2 & 115 & &  & &\\
J111552.01-000436.1 & 115 & &  & &\\
\multirow{3}{*}{J110731.23+134712.8} & \multirow{3}{*}{120} & MagE & 06/07/2017 & 2400& 1.3\\
 & & Fourstar & 10/07/2017 & 466 & 0.77\\
 & & Chandra & 17/07/2017 & 9960\\
\multirow{2}{*}{J134244.41+053056.1} & \multirow{2}{*}{153} & Mage & 30/05/2017 & &1.5\\
& & Fourstar & 09/07/2017  & 384 & 0.53\\
\hline

\end{tabular}
\caption{Log of observations of confirmed IMBHs performed in this study. 
\label{obslog}}
\end{table}