默认选中第一行第三列（序号和辖区不可点击选中），单选功能，点击其他单元格，当前选中的单元格取消选中，目前没有找到更好的方法来实现该功能，先保留现有的方法后面有了优化会更新！

<template>
<el-table
          :data="baseDataList"
          style="width: 100%"
          height="98%"
          class="pageTablePart" 
          highlight-current-row
          @cell-click="cellClick"
          ref="myTable"
        >
          <el-table-column
            width="50"
            align="center"
            type="index"
            label="序号"
          ></el-table-column>
          <el-table-column
            prop="areaId"
            label="辖区"
            align="center"
            :show-overflow-tooltip="true"
          ></el-table-column>
          <el-table-column
            v-for="(item, index) in tableHeader"
            :key="index"
            :prop="item.prop"
            align="center"
            :show-overflow-tooltip="true"
          >
            <template slot="header">
              <p>{{ item.date }}</p>
              <p>({{ item.holiday }})</p>
            </template>
          </el-table-column>
        </el-table>
</template>

<script> 
export default { 
  data() {
    return { 
      tableHeader: [
        {
          date: "09-30",
          holiday: "周五-国庆-班",
          prop: "one",
        },
        {
          date: "10-01",
          holiday: "周六-国庆-休",
          prop: "two",
        },
        {
          date: "10-02",
          holiday: "周日-国庆-休",
          prop: "three",
        },
        {
          date: "10-03",
          holiday: "周一-国庆-休",
          prop: "four",
        },
        {
          date: "10-04",
          holiday: "周二-国庆-休",
          prop: "five",
        },
        {
          date: "10-05",
          holiday: "周三-国庆-休",
          prop: "six",
        },
      ],
      baseDataList: [
        {
          areaId: "全市",
          one: "xxxxxxxxxxxxxxxx",
          two: "ccccccccccccccccc",
          three: "xxxxxxxxxxxxxxxx",
          four: "ccccccccccccccccc",
          five: "xxxxxxxxxxxxxxxx",
          six: "ccccccccccccccccc",
        },
        {
          areaId: "全市1",
          one: "xxxxxxxxxxxxxxxx",
          two: "ccccccccccccccccc",
          three: "xxxxxxxxxxxxxxxx",
          four: "ccccccccccccccccc",
          five: "xxxxxxxxxxxxxxxx",
          six: "ccccccccccccccccc",
        },
      ],
      
      tableBgColor: "var(--tableActive)",
      tableColor: "var(--totalNumColor)",
    };
  },
  mounted() {
     
    // 默认第一行，第二个选中（以下标为准）
    this.tableActive(0, 2);
    // 当表格动态生成时，防止样式错乱
    this.$nextTick(() => {
          // 初始化表格
        this.$refs.myTable.doLayout();
        this.tableActive(0, 2);
    });
  },

  methods: {
    // 指定表格选中哪一个（以下标为准）
    tableActive(row, column) {
      this.$nextTick(() => {
        let tableBox = document.getElementsByClassName(
          "el-table__body-wrapper"
        )[0];
        let trName = tableBox.getElementsByClassName("el-table__row")[row];
        let tdName = trName.getElementsByClassName("el-table__cell");
        tdName[column].style = "color:" + this.tableColor + "!important; background-color:" + this.tableBgColor + "!important";  
      });
    },
    
     
    // 某个表格点击事件
    cellClick(row, column, cell, event) { 
      if (column.label != "序号" && column.label != "辖区") { 
        if (cell.style.backgroundColor == this.tableColor) {
          // 取消选中
          cell.style = "background-color: transparent; color: auto";
        } else {
          // 先清除所有选中
          let tableBox = document.getElementsByClassName("tableWrapper")[0];
          let tdName = tableBox.getElementsByTagName("td");
          for (let i = 0; i < tdName.length; i++) {
            tdName[i].style = "background-color: transparent; color: auto";  
          }
          // 选中
          cell.style = "color:" + this.tableColor + "!important; background-color:" + this.tableBgColor + "!important";  
        }
      }
    },
     
  },
};
</script>