Is there any tool to read/parse/analyse samba logs ?
What type of information are you looking to get out of your samba logs?
Logwatch will send you a daily report of the errors and such that are in the samba logs.
If you're looking for file and share activity logs then you'll need to enable the vfs audit module in samba which will log this sort of information to your system logger. From there you can use any log analysis tool you want to parse and generate reports on it.
http://www.samba.org/samba/docs/man/Samba-HOWTO-Collection/VFS.html has more information on the vfs modules for samba.