The buzz at Arlington’s IOTA Club and Café on Saturday afternoon was palpable. A half hour before the doors opened for the big show, the line stretched down the block to Whitlow’s on Wilson. Was it a special Arcade Fire show? Nope. A closer look at the line revealed a number of attendees who were still many years from IOTA’s usual 21-and-over age limit. Ralph’s World had come to Arlington. IOTA’s regular weekend afternoon…