thats the positive and negative plugs on the coil. only after market items, rev limiter, rev counter etc etc plug onto them. they just use female bullit connectors and slide straight over the top.
the two round "pegs" shouldent have anything attached to them on the standard setup. They ( as rs250 said) are used for attaching a rev limiter
The other spade connecter should have a short white wire attached to it which goes to a small block object which is earthed. This is the supressor for the AEI ( stops you from interefing with your neighboors TV when you drive past . The car will still run without this connected however