Yes, indeed there is. Select the object and go to Effect>Distort & Transform>Transform. With the Move/Horizontal slider, insert the distance you wish to separate the objects by PLUS the length of the object, i.e. 10px squares with a separation of 10px will require an input of 20px, then enter the number of copies and click OK. This will give you the horizontal part of your grid. Go to Effect>Distort & Transform>Transform again and click OK when warned about transforming again. In the dialogue box do the same for the Vertical aspect, copies etc. and Bob's your uncle.