Layout Tab
If you don't change the Layout portion of the Files Selection window, then the files are written defragmented.
To leave the most space possible for additional sessions, Toast writes files defragmented.
In most cases the standard layout is adequate. However, for special purposes, you can change the order in which the files are written on the CD.
To move files:
Select the file or files you want to move, and then click Move to top or Move to bottom, as appropriate. Or you can drag files to the position you want.
Toast writes files located at the top of the list first (towards the inner part of the CD).

See Also:

Overview of Making an ISO 9660 Cross-platform Disc
Files Tab
Settings Tab
Appearance of Windows on the CD
Multisession Format--Importing a Session from a CD