Open Mach3mill, and go to Operator > Edit Button Script. Click on the Table Mode button. When the script editor window opens, copy the code.
Open your plasma profile, and choose Operator > Edit Button Script. Click on the Table Mode button. Paste the code from the mill button.
Close and Restart Mach3.
You might want to save a copy of the original plasma screen button code, especially if it's really different.