LyX ⇒ Adding notes in the table

[LyxQuestions]

Please see the attachment. Tables in academic papers tend to have notes below them. But how can I add that in lyx? Or is there some good Latex table template out there with notes that I can insert into Lyx?

In lyx, if I check "Multicolumn", then the boundaries between columns disappear, but I still can't write sentences across columns.