You are in a world of pain with mdbtools. It is not actively developed, there are 100s of bug reports on sourceforge and my personal experience with it is pretty bad. Your options are
- run isql under the debugger (gdb) and when it crashes, type "bt" (for back trace) then look in the code to see where it is failing and fix it.
gdb /usr/local/bin/isql dashboard now enter r (to run) and hit enter type help largetable and enter when it crashes hit bt and enter
that will tell you where it fell over and I'm betting somewhere in mdbtools. Now you need to get the source and work out what went wrong - you'll need to know C to do this.
- get some other method of reading mdbs like another MS Access ODBC driver but I only know of commercial ones for non-Windows platforms - that is what I did.