In a small bowl, whisk together 1/4 cup of the lemon juice, salt, garlic, pepper, basil, and oregano. Gradually add 3/4 cup of the olive oil, whisking constantly.
In a large bowl, combine the mushrooms and marinade and toss to coat evenly. Cover and refrigerate for at least 24 hours. Let come to room temperature before serving.
Preheat a grill to medium-high.
Skewer the cherry tomatoes. Drizzle the skewers with the remaining 1 tablespoon of lemon juice and olive oil. Place on the grill and grill just until the skins begin to char, about 3 minutes. Remove from the skewers.
Compose salad of lettuce, mushrooms, Bocconcini, salami, and grilled cherry tomatoes.