In Writer, if you insert a table in a document and right-click it, you'll see a context menu with "Size" and the "Row height" and "Column width". With them, you can set exactly the height/width you want. This is super useful when you want columns and rows to have a specific size.

However, these options do not exist in Impress. It is simply not possible to set the height of rows (or the width of columns) by providing a specific value.

So I propose Impress tables also support defining height/width by value, as in Writer.

This should not be too difficult to implement, since it is achievable via macros. So the API is already there, we're just lacking the UI.

To run the macro below, simply create an Impress document, insert a table and select it.

Sub TableWidth
  oTable = ThisComponent.CurrentSelection.getByIndex(0).Model
  oColumn = oTable.Columns.getByIndex(0)
  ' See original column size
  MsgBox oColumn.Size
  ' Change column size
  oColumn.Size = 1000
  MsgBox oColumn.Size
End Sub