The first piece of code creates a 2-D array with dimensions 5 x 7 (height x width) and fills the array with with values following a uniform distribution. Looks like they are asking you to set certain buckets in the 2-D array to 1.5.
The second piece of code creates a zero-filled 2-D array with dimensions (5 x 3) and also initializes a variable col to be an array of evenly-spaced values between 0 and 5.0. They are asking you to add this array to the first column of the zero-filled 2-D array.