let el = document.getElementsByClassName("el-table")[0];
  this.$nextTick(() => {
    el.scrollLeft = 1000000;//
  }, 10);
  

width is not adaptive. Writing 100% is calculated automatically, and if you assign a value to certain widths, these widths add up to exceed the width of the parent element before a horizontal scroll bar appears.
height is not adaptive. If you want to see the scroll bar all the time, write the dead height, or the parent element writes dead, and the table height is 100%. In this way, a horizontal scroll bar will appear if the width is not enough, and the meter head can be fixed at the same time. But in this way, the vertical scroll bar is displayed in the table.
has not been in touch with this for a long time. I hope it will be helpful to you. I'm going to be driven crazy by this table, too. I feel bad

use max-height to limit the maximum height. How is it possible? calculate the height occupied by table yourself. In created:

// this.clientHeight-
this.clientHeight = document.body.clientHeight - 299

on el-table:

:max-height="clientHeight"

this is equivalent to being fixed in a space at the height of the screen, and when there is a lot of data, you don't have to drag to the bottom to see the scroll bar.

limit the maximum height with max-height. Try

to return too much data. It is recommended to use paging, otherwise the display interaction will be very poor. Every time you have to drop down the scroll bar in the horizontal scroll bar.
the horizontal scroll bar in the table component. Because there are too many columns, even if you set max-width, for each column, there will still be a scroll bar, so you can't remove the scroll bar below. The limit of element-ui