Plot legend size often too large

[massimo ceraolo]

I remember that I've already created a ticket on this a few years ago, but i cannot find it anymore.
Sorry for possible duplication.
In the effort of make the best usage of our valuable desktop space, I propose to reconsider the legend layout.
See the enclosed picture: the plot is sacrificed to a huge legend. I propose the line spacing (so the vertical space legend occupation), when two rows are needed, to be reduced to a minimum.
Aldo the space above the first row could be slightly reduced: compare with the smaller space below "time (s)".