Hii Ansh 
Try Below Code

<template>
    <lightning-card title="Opportunity Pagination" icon-name="custom:custom11">
   
       <div class="slds-m-around_medium">
          <lightning-datatable 
             key-field="Id" 
             data={data}               
             columns={columns} 
             sorted-by={sortedBy}
             sorted-direction={sortedDirection} 
             onsort={sortColumns} 
             onrowaction={handleRowAction}
             onsave={handleSave}
             draft-values={draftValues}>
          </lightning-datatable>
          </br>
          <lightning-layout horizontal-align="space">
             <lightning-layout-item flexibility="auto">
                <lightning-button label="Previous" icon-name="utility:chevronleft" onclick={previousHandler}>
                </lightning-button>
             </lightning-layout-item>
             <lightning-layout-item flexibility="auto">
                Page {page} of {totalPage} total no of records-{totalRecountCount}
             </lightning-layout-item>
             <lightning-layout-item flexibility="auto">
                <lightning-button label="Next" icon-name="utility:chevronright" icon-position="right"
                   onclick={nextHandler}></lightning-button>
             </lightning-layout-item>
          </lightning-layout>
       </div>
    </lightning-card>
 </template>


import { LightningElement, track, api, wire } from 'lwc';
import getAllOpportunity from '@salesforce/apex/OppClass.getAllOpportunity';
import { ShowToastEvent } from 'lightning/platformShowToastEvent';
import { refreshApex } from '@salesforce/apex';
import { updateRecord } from 'lightning/uiRecordApi';
const columns = [{ label: 'Id', fieldName: 'Id'},{ label:"Opportunity Name",fieldName:"recordLink",type:"url",sortable:true,editable:true,
typeAttributes:{label:{fieldName:"Name"},tooltip:"Name",target:"_blank"}},
{ label: 'Stage', fieldName: 'StageName', type: 'Phone'},
{ label: 'Lead Source', fieldName: 'LeadSource', type: 'Text'},
{ label: 'Amount', fieldName: 'Amount', editable:true},
{ label: 'Type', fieldName: 'Type', type: 'Picklist'},
];
export default class Test3 extends LightningElement {
    @track error;
    @api sortedDirection = 'asc';
    @api sortedBy = 'Name';
  
    @track page = 1;
    @track items = [];
    @track data = [];
    @track columns;
    @track startingRecord = 1;
    @track endingRecord = 0;
    @track pageSize = 8;
    @track totalRecountCount = 0;
    @track totalPage = 0;
    
    @wire(getAllOpportunity, {sortBy: '$sortedBy', sortDirection: '$sortedDirection' })
    wiredAccounts({ error, data }) {
        if (data) {
            var ObjData = JSON.parse(JSON.stringify(data));
            
            this.items = ObjData;
            this.totalRecountCount = data.length;
            this.totalPage = Math.ceil(this.totalRecountCount / this.pageSize);
            this.data = this.items.slice(0, this.pageSize);
            this.endingRecord = this.pageSize;
            this.columns = columns;
            this.error = undefined;
        }
        else if (error) {
            this.error = error;
            this.data = undefined;
        }
    }
   
    
    previousHandler() {
        if (this.page > 1) {
            this.page = this.page - 1;
            this.displayRecordPerPage(this.page);
        }
    }
    nextHandler() {
        
        if ((this.page < this.totalPage) && this.page !== this.totalPage) {
            this.page = this.page + 1;
            this.displayRecordPerPage(this.page);
        }
        
    }
   
    displayRecordPerPage(page) {
        this.startingRecord = ((page - 1) * this.pageSize);
        this.endingRecord = (this.pageSize * page);
        this.endingRecord = (this.endingRecord > this.totalRecountCount)
            ? this.totalRecountCount : this.endingRecord;
        this.data = this.items.slice(this.startingRecord, this.endingRecord);
        this.startingRecord = this.startingRecord + 1;
    }
    sortColumns(event) {
        this.sortedBy = event.detail.fieldName;
        this.sortedDirection = event.detail.sortDirection;
        return refreshApex(this.result);
    }
   
    handleSave(event) {
        var recordInputs =  event.detail.draftValues.slice().map(draft => {
            var fields = Object.assign({}, draft);
            return { fields };
        });
   
        var promises = recordInputs.map(recordInput => updateRecord(recordInput));
       
        Promise.all(promises).then(data => {
            this.dispatchEvent(
                new ShowToastEvent({
                    title: 'Success..',
                    message: 'Record Updated',
                    variant: 'success'
                })
            );
             
             this.draftValues = [];
             return refreshApex(this.items);
        }).catch(error => {
            this.error=error;
            console.log(error);
            this.dispatchEvent(
                new ShowToastEvent({
                    title: 'Failed..',
                    message: 'Failed to Updated',
                    variant: 'error'
                })
            );
        });
    }
}


Apex
public class OppClass {
     @AuraEnabled(cacheable = true)
    public static List<Opportunity> getAllOpportunity(){
        List<Opportunity> accList =[Select Id,Name,StageName,LeadSource,Amount,type FROM Opportunity];
        return accList;
    }
}