SQL Developer Version 18.1.0.095 Bug Report
Oracle SQL Developer
Version 18.1.0.095
Build 095.1630
Java(TM) Platform 1.8.0_152
Oracle IDE 18.1.0.095.1630
When accessing the "Import data..." dialog from a table's context menu, if you try to import a delimited text file and uncheck the "Header" checkbox the first line of the text file is NOT omitted.
If you select your file from the filesystem with the "Browse" button and don't touch any of the settings, unchecking the "Header" checkbox actually works, omitting the first line. If you adjust any of the settings (like choosing 'delimited' as the file's format) the "Header" checkbox stops working.
This behaviour is confirmed in the latest version of SQL Developer. I was using version 4.1.1.19 Build MAIN-19.59 previosly and the "Header" checkbox worked flawlessly in all situations.