Open the attached Impress file. In both pages you'll find tables that are OLE
objects pasted from Writer.
If you double click on them they in fact will open as such, and you can see
there are some borders: they are 0,05 pt black (default). And in fact, when
showing the presentation, those borders are visible.
However, in the Impress "normal mode" they are NOT shown, and this happens at
any zoom factor: you can explode even to 500% visualization,with a couple of
table figures occupying almost all the screen space, but the borders are still
nowhere.
You have to enlarge them to at least 1 pt width (0,5 pt is not enough, still
invisible) to make them visible in normal mode (on page 2 there is a single
vertical line visible of such witdh).
Perhaps the objection is that is better to use a native impress table, but I
still find some problems with them: I cannot find a way to format numbers in
them as I do in Calc and writer tables, and I cannot find a way to modify or
create a table style in Impress (Those offered by default are nice but all very
similar)
Thanks for the attention.