Run the below scrip, It will release unused space from the datafiles of the respective tablespace.
column value new_val blksize
select value from v$parameter where name = 'db_block_size'
set pages 0
set lines 300
column cmd format a300 word_wrapped
select 'alter database datafile '''||file_name||''' resize ' ||
One point to be wary of: tables (also indexes, materialised views ..) are allocated more space as you INSERT data into those tables. When you DELETE, that space is only freed inside those allocations. Meaning that the space will be reused when you insert new rows into that same table. But it will not be reused by other objects (other tables for example).
Without understanding the nature of the data contained within this object contains, it is difficult to offer solid advice.
If this were a regular table, then yes; you would delete rows from it and thereby release space within the Tablespace.
The fact that a delete statement results in more data being written to this object makes me think it is non-standard;...