This is about the right amount. After adding your water and salt, let the dough sit covered with a damp kitchen towel or plastic wrap for five minutes or so to make sure that it’s fully hydrated, then add more water if it still feels dry.
Shaping an arepa is a two-handed process. If you’re a real expert, you can do it without a work surface, simply pressing it back and forth between your hands until it forms a disk about 1/4-inch thick and 4 to 6 inches wide. I find it easier to shape on a cutting board, using one hand to flatten and the other to shape. Once the arepas are formed, there are a few cooking options. A grill pan or actual grill are great, as is a flat, lightly buttered skillet (use cast iron or non-stick). Even easier is a panini press. Cheesy Arepas: Want to take your arepas to the next level? Try adding some cheese directly to the dough.