Download an executable from Releases section and put somewhere on your system (e.g. inside of $pATH).
Optionally to get latest code do go install github.com/gucio321/excel2tex/v2@latest
- Open LibreOffice Calc or Excel
- Select cells you'd like to put in you latex and Ctrl+C-copy them.

- Run excel2tex programm in your terminal or by double-click on windows (You can specify additional options - see here).
- Paste the output in your latex document and build it.

[INFO]: Welcome to excel2tex v3.0.0
Usage: excel2tex [FLAG]...
Flags:
-T, --title Title of the table (type: string; default: XXXXX)
-l, --label Label for the table (type: string)
-t, --trim Trim empty columns (useful if you copy only some specified columns e.g. A and C) (NOTE: considers the first (header) row only!) (type: bool; default: false)
-nb, --no-header-bold Do not bold first row (header) (type: bool; default: false)
-bc, --bold-first-column Bold first column (type: bool; default: false)
-npp, -do --data-only Do not generate latex preamble and postamble. Will return only tble body. Ignores title, label, column type, table type e.t.c. Useful for introducing data fixes. (type: bool; default: false)
-s Separator for table columns (latex table columns type) (type: string; default: c)
-legacy Use tabularx instead of longtable. (-s X recomended) (type: bool; default: false)
-f, --force Skip any data checks (when possible). (type: bool; default: false)
-v, --version Print version and exit (type: bool; default: false)
-h, --help show help (type: bool)
Excel is a registered trademark of Microsoft Corporation in the United States and/or other countries.