A gallant. Reduced from the image on the site, The History of Costume.

Somewhat after Gosson, Thomas Dekker, himself a fine playwright and author of pamphlets, wrote a satirical account of the way a "gallant" should behave at the playhouse:

Whether, therefore, the gatherers of the public or private playhouse stand to receive the afternoon's rent [charge for admission], let our gallant, having paid it, presently advance himself up to the throne of the stage. I mean not into the Lords' room, which is now but the stage's suburbs (no--those boxes, by the iniquity of custom, conspiracy of waiting-women and gentlemen-ushers that there sweat together, and the covetousness of sharers are contemptibly thrust into the rear and much new satin is there damned by being smothered to death in darkness), but on the very rushes where the comedy is to dance...

The Gull's Hornbook (1609).

Sharers
The actors who held shares in the company.
Rushes
Rushes were strewn on the stage to deaden the sound of footsteps.

But why should a gallant want to sit on the stage itself?