Is it possible to fix the height of a row (tr) on a table?
The problem appears when I shrink the window of the browser, some rows start playing around, and I can not
Your table width is 90% which is relative to it's container.
If you squeeze the page, you are probably squeezing the table width as well. The width of the cells reduce too and the browser compensate by increasing the height.
To have the height untouched, you have to make sure the widths of the cells can hold the intented content. Fixing the table width is probably something you want to try. Or perhaps play around with the min-width of the table.