A few thoughts Terry,
Once you set the tool table up the first time you should not do anything that is changing the differences between them. Of course if you
break or dull the tool you need to change the tool table by going thru the sequence of touching off the tools, or if you have a tool setter then change the particular tool offset manualy. Depends how you work , but if you use a work offset, you won't see a difference in the tool table because you didn't do anything to screw it up. The only difference is the location of the master tool from the part.
Also if you keep the values of the tool table after they are touched off you could always just change the tool table manualy, apply / save, if you do something that screws it up.
An exercise worth doing is to create the tool table, then check to see if there are any work offsets, then do what you want, but ONLY ONE STEP / or CHANGE at a time and see what the affect was ie; did the tool table values change, did the dro values for program/part/machine change, is there a fixture offset / is it different, what happens if one just changes the tool number while at home or at soem location, etc. You will learn a lot and it will keep out of the bars! Ou also should take a look at the first move depending on how the code was created ie; wizard
use and using diameter or radius mode and current Mach settings.
Frankly, it can get confusing quick especialy if you need to change screens to do things ( i use a modified lathe screen).
Remember all this is a fun thing,
RICH