Short answers, pulled from the story.
Mátyás Rákosi was the de facto leader of Hungary from 1948 to 1956, serving as General Secretary of the Hungarian Communist Party and later the Hungarian Working People's Party. He established a one-party state modeled on the Soviet Union under Stalin.
Salami tactics refers to the method by which Rákosi's Communists dismantled opposition parties piece by piece rather than all at once, removing members deemed uncooperative and forcing mergers until no independent political force remained. Historian Norman Stone suggested the term may have been coined by Zoltán Pfeiffer of the Hungarian Independence Party, as no verified Rákosi quotation using it has ever been found.
Rákosi was imprisoned for over fifteen years in Hungary. His first trial in 1926 sentenced him to eight and a half years; when that expired on the 24th of April 1934 he was immediately retried and sentenced to life imprisonment, before being released on the 30th of October 1940 in exchange for Hungarian revolutionary battle flags.
Rákosi was forced to resign as First Secretary on the 18th of July 1956 under pressure from the Soviet Politburo, triggered in part by Khrushchev's secret speech of February 1956 condemning Stalin's crimes and by growing domestic pressure including a letter from imprisoned secret police chief Gábor Péter naming Rákosi as responsible for unlawful show trials. Yugoslavia's Tito also demanded his removal as a condition of normalizing Hungarian-Yugoslav relations.
Rákosi was exiled to the Soviet Union in 1956 and was never permitted to return to Hungary. From 1964 to 1968 he lived in Tokmok in Soviet Kirghizia, where he worked as a manager in a wallpaper factory. In 1970 he refused an offer to return home on the condition of political silence, and he died in Gorky on the 5th of February 1971.
Rákosi is buried in the Farkasréti Cemetery in Budapest. His ashes were returned to Hungary in secret after his death, and only his initials appear on the gravestone to discourage vandalism, reflecting the deep antipathy his name still carries in Hungary.