If a Tokamak is essentially a "transformer" with the secondary being the plasma current. Would it be considered a "step up" or "step down" transformer?

 

No.

 

More like plasma excitation. When I worked in a clean room we use something called a plasma Asher which used 13.5 megahertz to excite a near vacuum gas (helium, nitrogen or oxygen) to a plasma which sandblasted the microelectronic circuits on molecular level. As I understand it the tokamak reactor is more of a linear accelerator. Exciting the gas to a plasma as well as accelerating it to a very high speed. That Wikipedia link took me all of 10 seconds to find.

 

If a Tokamak is essentially a "transformer" with the secondary being the plasma current.

No.
The output (mostly high-energy neutrons) will be absorbed by the chamber walls to power a steam generator with its corresponding low efficiency, not electricity directly.

Some other fusion generator approaches, such a pulsed plasma that have a hydrogen (proton)-boron aneutronic fusion, do not produce neutrons, only energic charged alpha particles, and the the proposal is to generate electricity directly from those charged particles.

 

A 'possible' commerical Tokamak like ITER requires constant plasma fusion so it doesn't operate with the old Soviet Tokamak pulsed inductive 'secondary' plasma current heating.
Bootstrap Current Operation in ITER

http://cds.cern.ch/record/1343736

https://www.iter.org/whatsnew/print/255

Recent research shows it should be possible to reach steady-state fusion production in ITER with the baseline mix of heating and current drive systems, in particular by upgrading the levels of power delivered to the plasma by neutral beam injection and electron cyclotron wave heating. 'One of the goals of ITER is to show that we can produce fusion power for an unlimited amount of time with high fusion gain (Q≥5)—so-called 'steady-state' operation,' says Alberto Loarte, Science Division Head. 'There are no physics or engineering hurdles holding us back.' But since ITER is an experimental facility, designed to facilitate a wide range of explorations, its baseline configuration is not optimized for steady-state operation. To achieve this, ITER will need to demonstrate operation with very high confinement—but not only. 'We will have to replace the inductive current provided by the central solenoid with plasma-driven current (bootstrap) and currents driven by neutral beam injection and electron cyclotron waves.