Tables created in the structure editor are referenced by a table number that are assigned sequentially such as the following:



When tables are deleted, 4D assigns new table numbers differently depending whether the "Trash" is emptied or not from the explorer window. Take for example the following tables deleted in the following order Table_2, Table_4, and Table_7:



If the "Trash" is not emptied, 4D will continue to assign the table number sequentially from the last table created which is "Table_8" as shown below:



If the "Trash" is emptied, 4D will take an account of deleted items and treat the assignment as a LIFO (Last In First Out) meaning that the last deleted table "Table_7" will be the first table number assigned on the next new table as shown below:



When the last table number has been created from that stored LIFO set, new table numbers will resume creating sequentially as by design.