No, our API doesn't support batches of addresses in one request. Each address is treated as one request and needs to be requested separately. You can, however send multiple API calls concurrently.
How many concurrent requests you can send will depend on the per-second limit associated with your account. If on the free plan, this limit is 2/second.
Our standard plans are available on our pricing page. If none of these work for you, send us a message and we'll arrange something that fits your requirement.