Returning Table Field Names

[ElPunto]

I am currently designing a system that is designed to take a table with field names that vary in each instance the table is used.

The fields each refer to a variable that is going to be overwritten as the index of the table is changed.

Example
[LUA]
Table = {A, B, C ,D} // One Instance Of The Table

Table = {A, B, C} // Another Instance (In A Different File)
[/LUA]

Is there anyway of returning the field names in a table so the variables can be overwritten.