How do I delete multiple duplicate data from the sheet?
There are a number of ways, depending on whether you want a one-time cleansing of an existing table (answer: use the Dedupe Block) or ongoing realtime deduplication (answer — or, at least, a suggestion: Use my data deduplication routines). There are also published instructions on doing so using such SaaS integration tools as Zapier – search the forum for ‘deduplication’.
Personally, I’m partial to my own system — for keeping a living, changing table free from duplicates, or for assisting in detection of ‘fuzzy’ duplicates (e.g., deduplicating data collected from multiple sources where one thing may be represented by multiple records that aren’t quite identical, such as detecting that ‘Jack Scearce, VP, Coca-Cola Corp’ and ‘Mr. John S. Scearce, Vice-President, Coca-Cola’ are the same person), I think they’re unsurpassed — but I’m admittedly biased.