、。
When dinner was over, he began reading the novel.
Literal
Dinner [subject-が] finish-[conditional-と], he [topic-は] that novel [object-を] read-begin-[past-めた].
Same ~と conditional template, ending in the compound 読み始める ('begin reading'). The compound ~始める attaches to a verb stem and is more neutral and deliberate than ~だす (which emphasizes suddenness). 彼 ('he') is used explicitly here — less common in Japanese than English, often signaling a shift in focus or emphasis on the individual.