Open your file in Inkscape, Adobe Illustrator or whatever program you have for designing. Then copy and paste. You will be able to lay out 70 efficiently on a 12 X 20 artboard, but depending on your engrave speeds, you may not be able to use the entire 12 x 20 area. If you copy and paste in the Glowforge interface, the Glowforge will treat each item as a unique item and your project time will be longer.
The Glowforge “sees” colors. If you make different elements of your design different colors, they will be treated separately - meaning you can assign different cut/score/engrave settings to each element. Suggestion - if you are engraving and cutting, perform the cuts last in case there is any board warpage that would allow the cut out item to drop lower than the uncut elements.
So I opened your file in Inkscape and duplicated the item. You already have everything separated by color. In the Glowfowge interface, this is what it looks like with three - each element will be performed across all three items, I believe.
If you do copy and paste in GF, copy and paste 5 or six then select all of them and copy and paste and it will then paste all 5 so you don’t have to do one at a time…then you’ll have 10 and can copy and paste all 10…