We have found one software suitable in our database for this conversion.
Contacts from Symbian phones saved in .cdb databases can be exported and saved as Excel spreadsheets (.xls) with dedicated Nokia (Symbian) utilities, such as the popular Noki or similar. Its as much as close as cdb to xls conversion as it can, but it's nothing else than extraction of content.
Updated: November 22, 2021
A small usefull program for exploring and extracting of files created with Nokia PC suite
CDB
Files with cdb suffix are contact databases commonly used in mobile phones with Symbian OS. These can also be found within backups created by Nokia PC Suite.
XLS
Files with xls extension are best known as spreadsheets from Microsoft Excel. A spreadsheet is basically a grid of cells sorted in rows and columns. Each cell can contain text, numeric or formula data. Excel XLS spreadsheets can be opened in most other similar programs, such as OpenOffice.org Calc.