From Homestar Runner Wiki
The Island is where Homestar and Strong Bad were stranded on in the Strong Bad Email island. It is surrounded by ocean and has a lone palm tree and a fern-like plant in its center. According to Strong Bad, it's "the worst deserted island ever".
Bubs took his Baloney Sammich Truck to the island in an attempt to sell baloney sandwiches in Weclome Back. He sold exactly zero baloney sandwiches and claims that it was pretty much his "best summer ever".
Strong Bad was marooned on the island as it was sinking, despite the fact that Strong Bad "didn't even beat any end bosses", but was saved by The Paper.