A table is a two dimensional array of atoms. Tables cannot be written directly as a constant as can an atom or a list, but instead must be created with a primitive. The dyad $ (shape) can create tables. The left argument indicates the count of items in each dimension and the right argument provides items to populate the table.
2 3 $ 7 NB. a 2 by 3 table of 7's 7 7 7 7 7 7 2 3 $ 7 8 9 10 11 12 7 8 9 10 11 12 2 3 $ 7 8 NB. cycle through atoms to get enough 7 8 7 8 7 8 3 4 $ 'abcdefghijklmnopqrstuv' abcd efgh ijkl
The monad $ (shape of) gives the shape of its argument. The shape is the list of the count of atoms in each dimension of the argument.
a =. 2 3 $ 7 $ a 2 3
The monad i. (integers), introduced earlier for creating a list of integers, can be used to create tables of integers.
i.5 NB. list of 5 integers 0 1 2 3 4 i. 2 3 NB. 2 by 3 table of integers 0 1 2 3 4 5