These were all the sons
ben (bane)
a son (as a builder of the family name), in the widest sense (of literal and figurative relationship, including grandson, subject, nation, quality or condition, etc.
of David
David (daw-veed')
loving; David, the youngest son of Jesse -- David.
beside the sons
ben (bane)
a son (as a builder of the family name), in the widest sense (of literal and figurative relationship, including grandson, subject, nation, quality or condition, etc.
of the concubines
piylegesh (pee-leh'-ghesh)
a concubine; also (masculine) a paramour -- concubine, paramour.
and Tamar
Tamar (taw-mawr')
Tamar, the name of three women and a place -- Tamar.
their sister
'achowth (aw-khoth')
a sister (used very widely, literally and figuratively) -- (an-)other, sister, together.