Is there a way to keep picture files external, keep them from being imbedded in CDR?

Stupid question from me, can I ask why you don't want them embedded?

Diana Jordan said:

I am trying to keep the CDR file size down. I successfully used Ventura Publisher for 20 years. There I could choose to leave the picture files external to the publisher document. In creating a 28 page magazine, I was able to produce manageable PDFs for the printer.

Now with CorelDraw 2018, every time I add a picture file internally to the CDR the file size jumps. At the moment, it is over 1GB. The PDF size is out of control.

But I just tested a CDR. With no JPG, the file size is 1991KB.

Adding a JPG of size 5400KB to the CDR, leaving it external, increased the size of the CDR to 16900KB.

I don't get it.

The problem is creating a press quality PDF for the printer. Way too big.

there's a common mistake about this, I'll try to explain

if you have a JPG image, while it's closed and compressed, the file size could be 5 Mb for example. If you open the file (with PhotoPaint or Photoshop) or place into another program (such as CorelDRAW or InDesign), the file will be un-compressed. So, the image size of the JPG could become to 20 Mb 50 Mb or 80 Mb according the file compression used.

Then, if you have 10 images at 80 Mb each, you will have 800 Mb, although each JPG could be just 5 Mb while  is closed and compressed. 

The PDF will be also big, according the file content.

Anyway, you could check the image resolution. You don't need more than 300 dpi of eah image at final size. If you convert to bitmap at 300 dpi, the file size surely will be smaller (1 Gb is too big, no matther the quality)