Everything points to the wk3 to excel conversion being searched by users that have data in old Lotus 1-2-3 spreadsheets (.wk3 from version 3) and that need to convert these to Excel.
Unfortunately, modern versions of Excel no longer support Lotus 1-2-3 files, which means your best option is to actually find and install Lotus 1-2-3 in virtual machine (Windows 3.11 / 95) and export your files to CSV or similar format that you can import to Excel. You can download Lotus 1-2-3 on abandonware websites, for example the WinWorld library.
Linux users can use Gnumeric, that supposedly still supports some legacy formats, including ones from Lotus 1-2-3.
Updated: September 13, 2023