Yes, NetMaster will show you all programs that are using your network in real-time. It will also provide you with long-term logs and statistics.
Yes, with NetMaster you can blacklist a program temporarily or permanently to prevent it from accessing the Internet.
By the way, NetMaster is available as a fully-functional 30-day trial that you can download from its home page. This means you can install and use if for the whole month absolutely free of any charge or obligations, check how these functions work and see if you are happy with all other features it offers.