<el-table-column prop="remark" label="备注" min-width="200">
          <template slot-scope="scope">
            <template>
              <span class="pre">{{ scope.row.remark }}</span>
            </template>
          </template>
        </el-table-column>
<style lang="scss" scoped>
.pre {
  white-space: pre-wrap;
  word-wrap: break-word;
}
</style>

添加样式即可换行