For images and drawing objects there is a context menu entry "Insert caption...". I suggest to add "Insert caption..." in the context menu for Writer tables too. In good writings, not only images should have a caption but also tables. LibO should support that easily. Context menu of drawing objects has 14 entries, the one for tables has 13 - so there is room for such improvement. :)
+1 from my side. The wording 'Insert Caption' is weird when Insert allows to manipulate rows/cols. So how about just 'Caption...'?
*** This bug has been marked as a duplicate of bug 87590 ***