There are a variety of synonyms that can be used in place of "light conversation" depending on the specific context or tone desired. Some options might include casual chat, small talk, friendly banter, idle chit-chat, simple pleasantries, or easygoing discussion. Other phrases that might work include relaxed exchange, effortless dialogue, informal discussion, or low-key discourse. Depending on the setting or situation, some synonyms might be more appropriate or effective than others, but all of these options can convey a sense of ease and informality in the communication.