Empty table cell format should not be removed

When you try to style the first word of a table cell, the format is applied to the whole cell. E.g.

|(% style="background-color:red" %)Some(%%) text|first line
second line

results in

Putting an empty format statement at the start of the cell

|(%%)(% style="background-color:red" %)Some(%%) text|first line
second line

prevents this:

Problem: When switching between source and visual mode of the CKEditor the empty format statement is removed by the renderer.