mtab is short for Mount Table. It is basically a list of devices that get mounted, some upon boot, some not, and their dev nodes. Also, it shows permissions, filesystem type, and some other stuff. It is generally the same as the fstab, but it partains to devices rather than filesystems.
On to Kudzu. it basically checks for new hardware and sets it up upon boot.
From the man page:
kudzu detects and configures new and/or changed hardware on a system.
When started, kudzu detects the current hardware, and checks it against
a database stored in /etc/sysconfig/hwconf, if one exists. It then
determines if any hardware has been added or removed from the system.
If so, it gives the users the opportunity to configure any added hard-
ware, and unconfigure any removed hardware. It then updates the
database in /etc/sysconfig/hwconf.
If no previous database exists, kudzu attempts to determine what
devices have already been configured, by looking at /etc/modules.conf,
/etc/sysconfig/network-scripts/, and /etc/X11/XF86Config.