Selectman Michael Berry said last week that he is resigning from the board as of June 6 because he doesn’t have the time to do the job well. Berry has two years left in his second term on the board. His announcement now leaves time for candidates to get on the ballot for the June 7 election. Berry said his position as chief of staff for the mayor of Marlborough, which he started in January 2012, has been increasingly time-consuming. “The last six months I felt like I wasn’t able to give enough time [to Walpole],” he said. “I was used to giving 150 percent and was only able to give 100 percent.” Berry, who served previously on the School Committee, said he hasn’t ruled out elective office in the future. “I’m sure the time will come when I get a little itchy and look forward to having something to do on Tuesday nights again. I’m only 30, so I hope I’m not over the hill,” he said.