You can have multiple variables in one scripting memory file:
|$productName|$orderNumber
tc01 |Bread |1
tc02 |Beer |14
tc03 |Beer |100
In your case, the variable names $xx and $yy can be placed in one scripting memory file as well.
|$xx|$yy
tc01_jump |jump |brain
tc02_run |run |leg
...
There are more examples in the Botium Docs