How to create a 2D Array in FPScript?

The simplest way is to use the FPScript Multiply operator:

0. # 1000
Creates a data series (vector) of 1000 64-Bit float values.

0. # 1000 # 100
Creates a data matrix with 100 coloms and 1000 rows.

To create a signal series, you can optionally assign an increasing X and Z component:
Signal(0. # 1000 # 100, 1, 1)

In thes example the X an Z components both start at 0 and have an increment of 1.