I have a spreadsheet with several rows with height greater than 10cm. The text in these cells are wrapped and have several lines. By default calc’s page break can only be in between two rows which results in blank space less than the height of next row in bottom of each printed page.
Can a page break be at middle of a cell in calc so that this can be avoided?
Definitly no!
To the best of my knowledge Calc cannot break a page within a cell; it would not make sense as Calc is a spreadsheet calculation program.
As it seems that you have larger text parts in Calc cells, I recommend to move these tables into a Writer file. There, text handling, formatting and page breaking is much easier.
When you copy and paste your table into Writer, you can try several formats to see which format serves your needs best. Copy in Calc and Paste Special in Writer and select the format you want. I personally use in this case the html-format to copy into a Writer file, which I save as an odt-file.