You can use 'Multi select' to align tables along any edge (top, bottom, right, left). You select a base table and, providing your table selections are logical, the others will be aligned with it along the edge you chose.
Consider this example. We will align tables 8, 9 and 10 along their top edge.
1. Click table 8.
2. Tick 'Multi select'.
3. Click table 9. Three new options appear at the top right: A drop down list, 'Align' and 'Same Size'.
4. Click table 10. All 3 tables are now selected.
5. From the drop down list, we can select 'Top', 'Bottom', 'Left' or 'Right'. Select 'Top'.
6. Click 'Align'. The result is that tables 8, 9 and 10 are now aligned with table 8's top edge.
7. Click 'Save' to save your changes.
To cancel the 'Multi select' mode, untick the box and click any table.