When my husband realized that I was cooking the clams on the BGE instead of steaming them, he said "what???" It was a great dinner and very simple to make.
Soak a cedar plank for about an hour or longer in water. While the plank soaked, I also soaked 2 ears of corn to make a grilled corn salad for a side. This is also a good time to get the Big Green Egg heating up. Once the grill was hot, I tossed the corn (in husks) on for the salad. Grilled corn salad can be as complicated or easy as you'd like. I went easy with just adding some mayo and pick-a-pepper hot sauce for dressing and adding in some of the ingredients from the clams (chopped parsley and shallots) and a squeeze of lime.
Once the corn is grilled, remove it to cool to room temp for the salad. Now it's time to add the lobster. Lightly brush olive oil on the cedar plank and on the lobster tails. Pepper and salt and put on the Big Green Egg.
After about 5 minutes or so, the clams can be added to the grill. I had roughly a pound of clams and splashed them with some white wine. Shut the lid and cook until the clams are open and the lobster is done. I used this clam recipe with the grilled bread (half recipe).