最后我意识到
在我输入并按下Tab键后，下一个单元格被聚焦。
但由于整个表是重装
由于来自CellEdited的row.update({ serviceHistory: JSONDataForServiceHistory });代码
细胞聚焦丢失。
所以我使用renderComplete函数并重新聚焦到所需的单元格。
现在它起作用了。

var JSON_DataSet_Empty_Child = [{ date: "", engineer: "", actions: "" }];

var JSON_DataSet_Empty = [{
    id: 1, make: "", model: "", reg: "", color: "", serviceHistory: JSON_DataSet_Empty_Child
}];

$(document).ready(function () {        
    Bind_tbl_BeamCageSchedule();        
});

function Bind_tbl_BeamCageSchedule() {
    //define table
    var table = new Tabulator("#tbl_BeamCageSchedule", {
        height: "100%",
        layout: "fitColumns",
        columnDefaults: {
            resizable: true,
        },
        data: JSON_DataSet_Empty,
        columns: [
            { title: "Make", field: "make", editor: "input" },
            { title: "Model", field: "model", editor: "input" },
            { title: "Registration", field: "reg", editor: "input" },
            { title: "Color", field: "color", editor: "input" },
        ],
        rowFormatter: function (row) {
            var position = table.getRowPosition(row);

            //create and style holder elements
            var holderEl = document.createElement("div");
            holderEl.classList.add("nested-table");

            holderEl.style.boxSizing = "border-box";
            holderEl.style.padding = "10px 30px 10px 10px";
            holderEl.style.borderTop = "1px solid #333";
            holderEl.style.borderBotom = "1px solid #333";
            
            /// remove previous nested table object                
            var row_element = row.getElement();
            var previous_nested_table = row_element.getElementsByClassName("nested-table");
            for (let child of previous_nested_table) {
                child.parentNode.removeChild(child);
            }

            var tableEl = document.createElement("div");                
            tableEl.setAttribute("id", "tbl_ServiceHistory" + position);
            tableEl.style.border = "1px solid #333";

            holderEl.appendChild(tableEl);

            row.getElement().appendChild(holderEl);

            var subTable = new Tabulator(holderEl, {
                layout: "fitColumns",
                data: row.getData().serviceHistory,
                columns: [
                    { title: "Date", field: "date", sorter: "date", editor: "input" },
                    { title: "Engineer", field: "engineer", editor: "input" },
                    { title: "Action", field: "actions", editor: "input" },
                ]
            });
        },
    });

    var LastEditedCell_ParentTable = null;
    table.on('cellEdited', (cell) => {
        MainTable_CellEdited(cell, table);
        LastEditedCell_ParentTable = cell;
    });
    
    // Re-focus the cursor after the table is fully loaded
    table.on("renderComplete", function () {
        if (LastEditedCell_ParentTable) {
            var cell = LastEditedCell_ParentTable;
            var row = cell.getRow();

            var currentColumn = cell.getColumn();
            var nextColumn = currentColumn.getNextColumn();

            if (nextColumn) {
                var nextCell = row.getCell(nextColumn.getField());
                nextCell.edit();
                nextCell.getElement().focus();
            }
        }       
    });
}

function MainTable_CellEdited(cell, table) {
    var row = cell.getRow();
    var cellvalue_make = row.getCell("make").getValue().trim();
    if (cellvalue_make.length > 0) {

        var JSONDataForServiceHistory = [
            { date: "22/05/2017", engineer: "Jimmy Brown", actions: "Aligned wheels" },
            { date: "11/02/2018", engineer: "Lotty Ferberson", actions: "Changed Oil" },
            { date: "04/04/2018", engineer: "Franco Martinez", actions: "Fixed Tracking" },
        ];

        row.update({ serviceHistory: JSONDataForServiceHistory });
    }
}

https://jsfiddle.net/qz1kpe2j/