Question: After an Aliya at Shabbos Mincha, should one keep the Tallit on?
Answer: ב"ה Shalom
The purpose of putting on a Tallit for an Aliya is not because there is an obligation to wear a Tallit, but because of Kvod HaTzibbur. According to the Mishna Berura (סי’ יד ס”ק יא) who says it is proper to wear a Tallit for Kvod HaTzibbur, he does not differentiate between Shachrit or Mincha. Nonetheless many places have the minhag of not wearing a Tallit for an Aliya during Mincha (. פסקי תשובות אורח חיים סימן קלט, ט. ) In any case, once a person is after the Aliya, the purpose for wearing the Tallit has ended and therefore there is no need any more to wear it and it may be removed. All the best