When you use Publish & Share/Disc to create your DVD, choose the option to burn the a Folder rather than directly to a disc.
You can then use the excellent free program ImgBurn to copy the VIDEO_TS folder that Premiere Elements produces to as many DVD discs as you need.
I am viewing your question from different perspective, that is, the issue that you face when you are ripping VOBs from a second DVD-VIDEO on DVD disc using Premiere Elements,
It is best to give the Premiere Elements version and computer operating system that it is running on. In the absence of that, I will generalize.
Assuming that you are using
Premiere Elements 12
"DVD Camera or Computer Drive"
Typically the Video Importer Save In: is C:\Users\Owner\Videos
Each of your DVD discs is going to have the same names for the ripped VOBs (VTS_01_1.VOB and so on depending on the duration of the movie). Consequently, after the ripping of the first DVD's VOBs and their save to Videos, you will end up with that "files already existing..." block for the ripping of the VOBs from the second DVD.
The answer is, for each DVD disc VOB ripping, to plan ahead and create and set for different folders in Videos in the Save In field of the Video Importer.
Please review and then let us know if that works for you. Please do not hesitate to ask if you need clarification on anything that I have written.