What does higher electron gain enthalpy mean here?
I take for granted that what you call "electron gain enthalpy" is generally described as "electron affinity". This is the energy gained (or lost) when an electron is added to an atom, ion or molecule. In general the electron affinity is a measure for the tendency of elements to form anions. The trouble is that you may find tables giving these numerical values as positive or negative values. For example, for fluorine $\ce{F}$, the electron affinity is $\pu{338 kJ/mol}$. But you may find books where the same affinity is given as $\pu{-338 kJ/mol}$. It depends on the sense you consider the reaction $\ce{A + e- -&gt; A-}$.