No, you use the EVENT SHEET EDITOR
Click on ADD EVENT then the SYSTEM icon. At the bottom of the window that opens there's a TIME catagory. Double-click EVERY X SECONDS. Enter how often you want to spawn a new object (1.5 is one and a half seconds etc).
After that click ADD ACTION next to the event you just added. Click the SYSTEM icon again and select CREATE OBJECT under GENERAL near the top. Then select the object you want to create and BOOM! you're done.
If you want to create the object at random times you would use the random statement. Instead of typing 1.5 for example type
That would get Construct to select a random number between 0 and 2 and spawn the object at that time instead. You can change the range to what you want (1,1.5) (2.5,5) ... and so on. I know you didn't ask for this last bit but I'm just telling you as an extra feature. ;)