The only way how you could achieve CSV to SBU conversion is to first import the contacts from the *.csv to your Samsung smartphone using the Samsung Kies software and then use the full phone backup function to completely backup your device. This will create an SBU backup archive that will also include the contacts from the previously imported CSV files.
Convert Comma Separated Value to Samsung Kies backup.
We have found 2 software records in our database eligible for .csv to .sbu file format conversion.
Microsoft Windows software - convert csv to sbu on Windows
A free software for managing of latest Samsung mobile devices
Convert from csv file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned csv to sbu. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
Apple macOS / Mac OS X software - convert csv to sbu on OS X
Management and sync utility for Samsung mobile devices