list manipulation - Generating an editable table that can be used as input

Say I have a number $n_{max}$. I want a command to generate a table like

1 1
2 2
3 3
4 4
...

nmax nmax

where the second column is editable, and this table can be evaluated so that Mathematica treats the table as the set

replacement = { 1 -> 1, 2 -> 2, ...}

(The point of this is so that I can replace the original list using /.replacement).

So for example, after generating the table above, I can edit the second column as follows

1 A
2 B
3 C

4 D
...
nmax FF

and this output re-evaluates into set

replacement = { 1-> A, 2-> B, 3-> C, F-> D, ... , nmax-> FF}