Snav Table Traversal

| a | a | a | | a | a | a | | a | a | a |

End of table traversal test

This test ensures the basic table traversal correctness of Spatial Navigation (SNav) algorithm:
focusable elements in a table element should be accessible.
* Navigation steps:

1. Loads this page, focus goes to "start" automatically.
2. Focus moves along through the sparsely positioned elements in the table, eventually going to an outer southward link,
   but going back inside the table later on.