Yes, this is done using the initiialize array function (on the array palette). If you drop the function on the diagram you will see that by default there is a dimension size input and an element input. If you want to create a 1D array of 20 elements of DBLs wire 20 to the dimension input and a double precision value of 0,0 (if you want all the 20 to be zero in the beginning) to the element input.
If you want the array to be 2D...3D etc. expand the function icon by resizing it (use the arrow cursor to grab the corner of it and resize...). It will then add size inputs for additional dimensions...
