A table must be created before it can be modified.
To modify an element of a table use the dot syntax.
The element need not exist before being set.
nM> get table1
T: TABLE1 = Table of 3 entries
L: ONE = 1
L: TWO = 2
L: THREE = 3
nM> set table1.ten 10
nM> get table1
T: TABLE1 = Table of 4 entries
L: ONE = 1
L: TWO = 2
L: THREE = 3
L: TEN = 10