matriz=[[1,2,4],[6,8,8],[9,10,12]]

matriz[0][0]=1

matriz[0][1]=2,3

matriz[0][2]=4,5,6,7

matriz[1][0]=8,9,10,11,12,13

matriz[1][1]=14,15,16,17,18,19,20,21

...

numeros=[[1,2,4],[6,8,8],[9,10,12]]
matriz = []

inicio = 1
for fila in numeros:
  m_fila = []
  for n in fila:
    m_fila.append(tuple(range(inicio, inicio+n)))
    inicio += n
  matriz.append(m_fila)

>>> matriz
[[(1,), (2, 3), (4, 5, 6, 7)],
 [(8, 9, 10, 11, 12, 13),
  (14, 15, 16, 17, 18, 19, 20, 21),
  (22, 23, 24, 25, 26, 27, 28, 29)],
 [(30, 31, 32, 33, 34, 35, 36, 37, 38),
  (39, 40, 41, 42, 43, 44, 45, 46, 47, 48),
  (49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60)]]

import numpy as np
numeros=np.array([[1,2,4],[6,8,8],[9,10,12]])
matriz = np.zeros(numeros.shape, dtype=object)

inicio = 1
for i, fila in enumerate(numeros):
  for j, n in enumerate(fila):
    matriz[i][j] = tuple(range(inicio, inicio+n))
    inicio += n

>>> print(matriz)
[[(1,) (2, 3) (4, 5, 6, 7)]
 [(8, 9, 10, 11, 12, 13) (14, 15, 16, 17, 18, 19, 20, 21)
  (22, 23, 24, 25, 26, 27, 28, 29)]
 [(30, 31, 32, 33, 34, 35, 36, 37, 38)
  (39, 40, 41, 42, 43, 44, 45, 46, 47, 48)
  (49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60)]]