Also see katakana
When a table cell has a third line, that line takes two forms - no parentheses or with parentheses. When it has no parentheses like "dsa" then it is an explanation of the pronunciation. When it has parentheses then it is how it is entered with an IME. If it is like "(wo)" then "wo" is how it is entered.
っ (っ is smaller than つ) stretches the consonant after it. For example がっこう is "gakkou" in romaji. For keyboard entry, double the following consonant. Entering "xtu" also works.
For more, see Wikipedia's hiragana page.
Voice: