spam =

   Data             cat1         cat2         time
__________          ___________  __________   ______

  -0.41763          1            0            0
   0.11719          1            0            0
  ...               ...          ...          ...
  -0.16546          1            0            1
  ...               ...          ...          ...
  -0.21763          1            0            2
   0.31719          2            0            0
  ...               ...          ...          ...
   0.58116          3            1            0
  ...               ...          ...          ...

spam = unstack(spam, 'Data', 'time')
Warning: Variable names were modified to make them valid MATLAB identifiers.

spam =
cat1       cat2        x0             x1         x2
______    _________    ___________    _______    ________

1         0            -7.6605e-15     2.3168     0.45234
2         0             6.2172e-15     5.1661     24.89
3         1             8.8818e-16     56.697     40.441
4         1            -7.9936e-15    -22.741    -17.191
5         1            -1.4433e-15    -7.7803    -20.817
6         2             5.5511e-16     7.8535    -0.21172
7         2             5.3291e-15     13.658     5.8402
8         2             2.2204e-15     9.1739     13.814