When copying columns and inserting them in the middle of a table, OnlyOffice does not provide the option to insert the copied columns in the middle of a table by moving the columns located to the right in order to create the necessary space to the inserted columns. This issue was previously reported in the following thread but with rows: https://community.onlyoffice.com/t/feature-request-spreadsheet-possibility-to-insert-copied-lines/4177
In my opinion, the lack of this feature reduce considerably the usability of OnlyOffice, since this is something done very often in a spreadsheet, so I encourage the OnlyOffice team to introduce it in future versions. Thanks!