Do ISO's contain partition tables as well as a backup of the data?

CD-Rs normally use the ISO-9660 filesystem directly, without partitions. I'm not familiar with the specific programs referenced in the question, so I can't comment on what they do, but some programs with which I am familiar do a file-level copy when creating a USB flash drive from a CD-R or an image file.

DVDs generally use the ISO-9660 filesystem and/or the UDF filesystem. The story here is similar: No partitions.

There are exceptions to this rule, though. Some Mac discs are written with a partition table and HFS or HFS+ instead of or in addition to ISO-9660. Such discs use the Apple Partition Map (APM) partition table. Some Linux distributions' installer discs use ISO-9660 that coexists with a partition table, but the intent here is to support different media in differnt ways -- when the image is burned to a CD-R or DVD, it appears to be a partitionless ISO-9660 disc; but when it's written to a USB flash drive, it appears to be a partitioned hard disk. This trickery works because of gaps in various data structures and the different sector sizes used on optical media (2048 bytes) vs. hard disks and USB flash drives (512 bytes). Both of these examples (Mac discs and Linux installation discs) are hackish extensions to the standards of ISO-9660, MBR partitions, and so on.

No, ISO's do not contain a partition table. The ISO file is, in effect, roughy equivalent to a partition. In fact, from the look of i both these programs appears to be copying the files off the ISO and onto the USB disk, rather then writing the ISO image directly to the disk.