When you set up the Tablo, you are just entering the SSID (WiFi name) and password of your currently running wireless network. This wireless network is run by your modem / router, which you had before the Tablo. The type of security is dictated by how you setup your modem / router. The Tablo does not broadcast it's own WiFi network, it just connects to your current one.
What is the make and model of your router?