Tizen Forums

The emulator currently supports screen size (skin) for phone layout only.  But you can use the Tizen simulator (if the app is purely based of HTML5 and JavaScript code) to try and test the UI design for the Tablet screen size. To configure the emulator, use the configuration option from the top right corner of the simulator and under "Device" section, define the custom resolution to that of the tablet screen resolution you want to test. 

If you wnat to use the emulator features, would suggest to try using the Intel's new XDK, which is a cross-platform development tool to build HTML5 applications for different platforms (form factor also includes Tablets). The XDK also supports Tizen.

Intel's XDK can be downloaded from here, http://xdk-software.intel.com/index.html

Another option, request for the Tablet development unit here,  https://developer.tizen.org/support/development-unit-program/available-development-units

You can also contact Linux Foundation or contact brian warner, who is linked on the development unit program.