This device is a "Web Pad" (as it says), i.e. an early tablet computer designed to provide wireless internet access. These devices were tossed around a lot in ≈2000/2001 but didn't really catch on. Other devices that fall into this category are the
Pepper Pad or
SIMpad.
One of the device's slots is a PCMCIA slot. This slot can be used for a Bluetooth card, WiFi adapter, or basically anything that is available in that form factor (ethernet, modem, flash memory cards, ...).
The device has an on-screen keyboard. And the modem is only required if you don't have wireless internet, which this kind of device was specifically designed to leverage.
The patent application shows one way of using the device. But it's basically a full-blown x86 computer running Linux. It will run Windows if you need it to. So it can be used for pretty much anything. It's like a laptop with a touchscreen but without keyboard and mouse.