I just tried this with MIDI data, and cannot get the hole to delete on a MIDI track. The only way I could do it was to split the track, delete the data, and slide the other MIDI data left (with snap to grid off). The delete hole only seems to work with audio data for me.
The Snap to Grid value is in the command bar (at the top of the screen by default, hidden/unhidden with "C"). By default the Snap Module is the second from the left.