Who is the member of the Thirty who was the son of Dodo, he was also from Bethlehem?

The son of Dodo from Bethlehem is Elhanan.

Source: 2^nd Samuel 21:19, 1^st Chronicles 11:26

Who among the Thirty killed a very tall Egyptian?

Benaiah was a renowned warrior among the Thirty. He killed an Egyptian about 7 feet (213 cm) tall.

Source: 2^nd Samuel 23:21, 1^st Chronicles 11:22

Which member of the Thirty was killed at David’s order?

Uriah the Hittite husband to Bathsheba was killed at David’s order. This was to cover up David’s affair with Bathsheba.

Source: 2^nd Samuel 23:39, 1^st Chronicles 11:41

After The Three was a group called The Thirty. Who was chief of The Thirty?

The Thirty were lead by Abishai brother of Joab and a nephew to David.

Source: 2^nd Samuel 23:18, 1^st Chronicles 11:20

The Three gave King David a special gift. What was the gift?

The gift was a cup of water from the well at Bethlehem. They had to fight through the camp of the Philistines to get it. David refused the gift and poured it out as an offering to the Lord.

Source: 2^nd Samuel 23:15-17