I load Open Office with my Excel spreadsheets. I then copy the spreadsheet ( or part of it) and paste it into the forum editor. It works very well except if I use Firefox browser. If I use Chrome or Edge to work the forum when I am pasting, all is well. Spreadsheets opened in Excel do not copy/paste well on the forum. It is a problem with Excel. Copying and pasting from most other spreadsheet programs works well.