Preheat barbecue (medium heat).
Brush tomatoes, corn and onion with oil; sprinkle lightly with salt and pepper. Place on grill. Grill until corn is slightly charred, onion is tender, and tomato skins are blistered- turning often. Transfer to baking sheet and cool.
Core tomatoes and cut in half. Gently remove the juices and seeds. Coarsely dice tomato flesh and place in medium bowl. Cut corn kernels from cob; add corn to tomatoes. Chop onion; add to tomatoes/corn mixture. Mix in garlic, lime juice, paprika, and 1 tablespoon oil. Season to taste with salt and pepper. Tomato mixture can be made a day ahead.
Brush bread with oil; sprinkle with salt and pepper. Grill until just golden on edges and grill marks appear, about 1 to 2 minutes per side.