Thought it was.
In your create table/index scripts you can define the max number extents allowable (looks like it has been set to 100 in your case), an extent is like an area of disk space you allocate. You can set the amount of space for each extent, how much each extent can grow by (percentage increase compared to the previous extent etc.).
For example suppose each extent is set at 1Meg, as soon as that 1Meg is full it moves onto another extent, so on and so on...
Is there a DBA available to you?
If so the DBA may have limited the max extents, speak to the DBA and work out how much space your indexing will take and set the extents appropriately, or remove the max extents limit.
Mike